WO2008116937A2 - Nucleic acids - Google Patents

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Publication number
WO2008116937A2
WO2008116937A2 PCT/EP2008/053761 EP2008053761W WO2008116937A2 WO 2008116937 A2 WO2008116937 A2 WO 2008116937A2 EP 2008053761 W EP2008053761 W EP 2008053761W WO 2008116937 A2 WO2008116937 A2 WO 2008116937A2
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Prior art keywords
epitope
nucleic acid
responses
cell
immunobody
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PCT/EP2008/053761
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English (en)
French (fr)
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WO2008116937A3 (en
Inventor
Linda Gillian Durrant
Rachael Louise Metheringham
Victoria Anne Pudney
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Scancell Limited
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Priority to ES08735583.0T priority Critical patent/ES2638188T3/es
Priority to JP2010500296A priority patent/JP5415399B2/ja
Application filed by Scancell Limited filed Critical Scancell Limited
Priority to KR1020157000952A priority patent/KR20150013357A/ko
Priority to CN200880017669.4A priority patent/CN101678092B/zh
Priority to DK08735583.0T priority patent/DK2134357T3/en
Priority to PL08735583T priority patent/PL2134357T3/pl
Priority to EP08735583.0A priority patent/EP2134357B1/de
Priority to AU2008231723A priority patent/AU2008231723B2/en
Priority to KR1020167020295A priority patent/KR101729458B1/ko
Priority to KR1020177009184A priority patent/KR20170040387A/ko
Priority to CA2681531A priority patent/CA2681531C/en
Priority to BRPI0808599A priority patent/BRPI0808599A2/pt
Publication of WO2008116937A2 publication Critical patent/WO2008116937A2/en
Publication of WO2008116937A3 publication Critical patent/WO2008116937A3/en
Priority to US12/566,465 priority patent/US8742088B2/en
Priority to ZA2009/07242A priority patent/ZA200907242B/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
    • C07H21/00—Compounds containing two or more mononucleotide units having separate phosphate or polyphosphate groups linked by saccharide radicals of nucleoside groups, e.g. nucleic acids
    • C07H21/04—Compounds containing two or more mononucleotide units having separate phosphate or polyphosphate groups linked by saccharide radicals of nucleoside groups, e.g. nucleic acids with deoxyribosyl as saccharide radical
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    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/85—Vectors or expression systems specially adapted for eukaryotic hosts for animal cells
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/0005—Vertebrate antigens
    • A61K39/0011—Cancer antigens
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/12—Viral antigens
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/12—Viral antigens
    • A61K39/145—Orthomyxoviridae, e.g. influenza virus
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/12—Viral antigens
    • A61K39/29—Hepatitis virus
    • A61K39/292—Serum hepatitis virus, hepatitis B virus, e.g. Australia antigen
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K39/385—Haptens or antigens, bound to carriers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/12—Antivirals
    • A61P31/14—Antivirals for RNA viruses
    • A61P31/18—Antivirals for RNA viruses for HIV
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • A61P35/02—Antineoplastic agents specific for leukemia
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P37/00—Drugs for immunological or allergic disorders
    • A61P37/02—Immunomodulators
    • A61P37/04—Immunostimulants
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N5/00—Undifferentiated human, animal or plant cells, e.g. cell lines; Tissues; Cultivation or maintenance thereof; Culture media therefor
    • C12N5/06—Animal cells or tissues; Human cells or tissues
    • C12N5/0602—Vertebrate cells
    • C12N5/0625—Epidermal cells, skin cells; Cells of the oral mucosa
    • C12N5/0629—Keratinocytes; Whole skin
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    • C12N5/00—Undifferentiated human, animal or plant cells, e.g. cell lines; Tissues; Cultivation or maintenance thereof; Culture media therefor
    • C12N5/06—Animal cells or tissues; Human cells or tissues
    • C12N5/0602—Vertebrate cells
    • C12N5/0634—Cells from the blood or the immune system
    • C12N5/0639—Dendritic cells, e.g. Langherhans cells in the epidermis
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/51—Medicinal preparations containing antigens or antibodies comprising whole cells, viruses or DNA/RNA
    • A61K2039/53—DNA (RNA) vaccination
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/54—Medicinal preparations containing antigens or antibodies characterised by the route of administration
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/555—Medicinal preparations containing antigens or antibodies characterised by a specific combination antigen/adjuvant
    • A61K2039/55511—Organic adjuvants
    • A61K2039/55566—Emulsions, e.g. Freund's adjuvant, MF59
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/60—Medicinal preparations containing antigens or antibodies characteristics by the carrier linked to the antigen
    • A61K2039/6031—Proteins
    • A61K2039/6056—Antibodies
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/70—Multivalent vaccine
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K19/00—Hybrid peptides, i.e. peptides covalently bound to nucleic acids, or non-covalently bound protein-protein complexes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2318/00—Antibody mimetics or scaffolds
    • C07K2318/10—Immunoglobulin or domain(s) thereof as scaffolds for inserted non-Ig peptide sequences, e.g. for vaccination purposes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
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    • C12N2510/00—Genetically modified cells
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    • C12N2730/00—Reverse transcribing DNA viruses
    • C12N2730/00011—Details
    • C12N2730/10011—Hepadnaviridae
    • C12N2730/10111—Orthohepadnavirus, e.g. hepatitis B virus
    • C12N2730/10134—Use of virus or viral component as vaccine, e.g. live-attenuated or inactivated virus, VLP, viral protein
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N2760/00—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA ssRNA viruses negative-sense
    • C12N2760/00011—Details
    • C12N2760/16011—Orthomyxoviridae
    • C12N2760/16111—Influenzavirus A, i.e. influenza A virus
    • C12N2760/16134—Use of virus or viral component as vaccine, e.g. live-attenuated or inactivated virus, VLP, viral protein

Definitions

  • the present invention relates to nucleic acids and to their use as vaccines, the nucleic acids encoding T cell epitopes against which an immune response is to be raised. Such vaccines may be used in the treatment of tumours.
  • TIL tumour infiltrating lymphocytes
  • WO 96/19584 discloses chimeric antibodies in which T cell epitopes are inserted into the complementarity determining regions (CDRs) of an antibody, and alleges that such chimeric antibodies are suitable for raising a cytotoxic T cell (CTL) response.
  • CDRs complementarity determining regions
  • this document teaches that the DNA must encode a functional protein.
  • US Patent No. 7,067,110 discloses a method for eliciting an immune response against an antigen using a fusion protein of antibody which lacks an immunoglobulin variable region domain fused to the antigen by a polypeptide bond.
  • the fusion protein retains the ability to bind to Fc.
  • EP0759944 discloses a method of incorporating T cell epitopes within an antibody molecule that is secreted as an intact immunoglobulin protein and which can target CTL epitopes to tumours to make them better targets for CTLs.
  • WO 00/64488 discloses that a CTL response can be raised by nucleic acid encoding a chimeric antibody having heterologous T cell epitopes inserted in the CDRs but not the variable region thereof, provided that the nucleic acid is directed for expression in B cells.
  • the vaccine described in WO 00/64488 would only be useful in boosting pre-existing T cell responses.
  • WO 02/092126 discloses that a CTL response can be raised by a polypeptide comprising a heterologous T cell epitope and the part of human Fc which binds to the high affinity CD64 receptor.
  • the present inventors have now shown that disruption of the antibody sequence by inserting a T cell epitope, for example within an inappropriate CDR or even within the variable region of an antibody, prevents association of heavy and light chain and no functional antibody is secreted.
  • DNA encoding these mis-folded antibodies unexpectedly generates strong T cell responses. Furthermore, this is not mediated via CD64 as human lgG2 - which does not bind to mouse or human CD64 - works just as efficiently as human IgGI .
  • nucleic acid which comprises a non-specific promoter and at least one sequence that encodes a polypeptide that has at least one heterologous T cell epitope therein but does not have any regulatory T cell epitopes.
  • This polypeptide is preferably a homologous carrier, e.g. when used to raise a T cell response in humans it may be a human protein, or a foreign protein or human/foreign chimeric protein that has had all T regulatory epitopes identified and removed.
  • the polypeptide is preferably one chain of a heterodimer, the heterologous T cell epitope causing disruption of the heterodimer chain such that it cannot bind or associate with the other chain of the heterodimer.
  • Many molecules are herodimeric, with one chain being dependent upon the other for folding and then secretion. If the secondary structure is disrupted due to insertion of a heterologous T cell epitope, folding and secretion is inhibited.
  • one chain is secreted and includes a heterologous CTL epitope, and the other chain includes a heterologous helper epitope but, due to disruption of the secondary folding, is not secreted.
  • the nucleic acid may encode both chains of the heterodimer, wherein one chain includes a heterologous cytotoxic T cell (CTL) epitope and is secreted when expressed, and the other chain includes a heterologous helper epitope and is not secreted when expressed.
  • CTL cytotoxic T cell
  • the respective heterodimer chains may be encoded on separate nucleic acid molecules.
  • the heterodimer may be an immunoglobulin molecule.
  • the heavy chain of the immunoglobulin molecule may include a heterologous cytotoxic T cell (CTL) epitope and be secreted when expressed, and the light chain of the immunoglobulin molecule may include a heterologous helper epitope and not be secreted when expressed.
  • CTL cytotoxic T cell
  • the nucleic acid of the first aspect of the present invention encodes an polypeptide that does not include any regulatory T cell (T reg) epitopes.
  • polypeptides act as inert carriers for the T cell epitope(s) and may be a molecule, or part of a molecule, that can be used by the immune system to stimulate immune responses, as these molecules by definition do not express competing T reg epitopes.
  • Suitable molecules include HLA molecules, T cell receptors, TOL receptors, TOL ligands, cytokines, cytokine receptors, chemokines, chemokine receptors. It is preferred that the molecule is an antibody or part thereof.
  • the present invention is based, at least in part, on the concept that a T cell response can be generated against a specific T cell epitope (such as a CTL epitope), by administration of a nucleic acid encoding a polypeptide including the T cell epitope but no regulatory T cell epitopes. It is believed that nucleic acid is either taken up by antigen presenting cells (APCs), migrates to lymph nodes and is directly presented, or is expressed to produce a polypeptide which is secreted and which is then taken up by other APCs. The former nucleic acid is suitable for stimulating helper T cell epitopes and the latter is suitable for stimulating CTL responses.
  • APCs antigen presenting cells
  • polypeptide that is encoded by the nucleic acid ideally does not have any natural T cell epitopes.
  • Suitable polypeptides in this regard are immune molecules, such as antibodies.
  • Antibody heavy and light chains which cannot associate so that the light chain remains in the APCs and so that the heavy chain is secreted are suitable for the practice of the present invention, although the present invention is not limited to the use of antibodies as carriers for the T cell epitopes.
  • Treg-cell depletion augments tumour immunotherapy including vaccination (Tanaka, et al, J. Immunother. 2002;25:207-217, Dannull et al, J. Clin. Invest. 2005;1 15:3623-3633) and CTLA-4 blockade (Sutmuller et al, J. Exp. Med. 2001 ;194:823-832).
  • Treg-cells are increased in the peripheral blood (Woo et al, Cancer Research 2001 ;61 :4766-4772, Curiel et al, Nature Medicine 2004;10:942-949, Wolf et al, Clin. Cancer Research 2003;9:606- 612, Sasada et al, Cancer 2003;98:1089-1099) and populate the tumour microenvironment and draining lymph nodes (Curiel et al, Nature Medicine
  • Treg-cells have also been shown to suppress/inhibit the proliferation, cytokine-production (IFN ⁇ , IL- 2) and cytolytic activity of tumour-specific CD8 + (Liyanage et al, J. Immunology 2002 ⁇ 69:2756-2761 , Piccirillo et al, J.
  • Treg- cells can suppress the functions of dendritic cells (Romagnani et al, Eur. J. Immunol.
  • Treg-cells are divided into natural CD4 + CD25 + T cells and diverse populations of induced/adaptive Treg-cells (Shevach, Immunity 2006; 25: 195-201 , Bluestone et al, Nat. Immunol. 2005;6:345-352) (Table 1 ). About 5%-10% of CD4 + T cells in mice and humans are natural Treg-cells (Sakaguchi et al, Nat. Immunology 2005 ;6:345-352).
  • Treg-cells develop in the thymus by strong TCR interaction with self peptide (Picca et al, Current Opinion in Immunology 2005;17:131 -136, Jordan et al, Nature Immunology 2001 ;2(4):301 -306, Picca et al, Immunological Reviews 2006;212:74-85), while induced Treg-cells develop from non-regulatory T cells in the periphery.
  • This extrathymic conversion requires special immunological conditions such as continuous exposure to low dose antigen, exposure to a systemic peripheral antigen or exposure to TGF ⁇ (Shevach, Immunity 2006; 25: 195- 201 , Akbar et al, Nat. Rev. Immunol. 2007;7:231 -237).
  • Treg-cells may mediate their suppression by one or a combination of the following mechanisms: i) cell-cell contact dependent mechanism, ii) through the secretion of immunosuppressive cytokines like IL-10 or TGF ⁇ or iii) direct killing of the target cells perforin-granzyme pathway (von Boehmer, Nature Immunology 2005 ;6(4):338-344).
  • Vence et al were the first to demonstrate the presence of NY-ESO-1 -specific Treg-cell epitopes within the NY-ESO-1 molecule. Furthermore, vaccination of melanoma patients with dendritic cells either loaded with synthetic peptides or tumour lysates was shown to induce increased frequencies of Treg-cells, concomitant with the expansion of tumour-specific CD8 + T cells (Chakraborty et al, Hum. Immunology 2004;65:794-802).
  • Treg-cell T cell receptor TCR
  • Treg-cells require antigen-specific activation through TCR recognition/engagement but mediate antigen-nonspecific bystander suppression (Thorton & Shevach, J. Immunology 2000; 164: 183190).
  • Li et al suggested the existence of dominant Treg epitopes within the Hepatitis C Virus core protein that stimulated HCV-specific Treg-cells in infected patients (Li et al, Immunol. Cell Biol.
  • Treg-cell epitopes as well as the CD8 + epitope. This would explain the failure of the vaccine to break tolerance to the self antigen Tie-2 and to elicit anti-tumour immunity in HHD mice due to abundant antigen-specific expanded Treg-cells suppressing the cell-mediated anti-tumour immune response.
  • T effector epitopes with inert immune carriers which fail to express T reg epitopes to direct the immune response to the effector epitope and prevent stimulation of the dominant T reg response.
  • the nucleic acid of the present invention includes a sequence encoding a sequence, such as a leader sequence, that allows the expressed polynucleotide to be secreted.
  • a sequence such as a leader sequence
  • the sequence could be a leader sequence that is naturally expressed with the polynucleotide or could be a heterologous leader sequence, such as an immunoglobulin leader sequence, which is added. The latter is especially suitable where the polynucleotide encodes a membrane-bound molecule.
  • nucleic acid which comprises a non-specific promoter and at least one sequence that encodes a recombinant heavy chain of an immunoglobulin molecule, wherein the heavy chain has at least one heterologous T cell epitope therein such that the heavy chain cannot take its native conformation when the nucleic acid is expressed.
  • the nucleic acid of the this aspect of the present invention encodes a recombinant heavy chain of an immunoglobulin molecule.
  • the structure of such a heavy chain is known to those of skill in the art, and generally includes variable and constant regions.
  • the heavy chain may be from an antibody.
  • the antibody may be monoclonal or polyclonal and may be IgA, IgD, IgE, IgG or IgM, although IgG is preferred.
  • the IgG antibody may be any IgG subclass, such as human IgGI , lgG2, lgG3 or lgG4, or mouse IgGI , lgG2a, lgG2b or lgG3.
  • the IgG antibody may be a human IgGI antibody having the lgG2 Fc binding domain, or a human lgG2 antibody having the IgGI Fc binding domain.
  • the heavy chain may have the constant region of a human antibody, and the variable or hypervariable (CDR) region of a mouse monoclonal antibody into which heterologous T cell epitopes have been inserted.
  • the variable region other than the hypervariable region may also be derived from the variable region of a human antibody.
  • the antibody When applied to antibodies (i.e. comprising a heavy chain and a light chain), the antibody is said to be humanised. Methods for making humanised antibodies are known in the art. Methods are described, for example, in Winter, U.S. Patent No. 5,225,539.
  • the variable region of the heavy chain outside of the mouse hypervariable region may also be derived from a mouse monoclonal antibody.
  • variable region is derived from murine monoclonal antibody and, when applied to antibodies, the antibody is said to be chimerised.
  • Methods for making chimehsed antibodies are known in the art. Such methods include, for example, those described in U.S. patents by Boss (Celltech) and by Cabilly (Genentech). See also U.S. Patent Nos. 4,816,397 and 4,816,567, respectively.
  • the nucleic acid of the present invention further comprises at least one sequence that encodes a light chain of an immunoglobulin molecule.
  • a separate nucleic acid encoding a light chain of an immunoglobulin molecule may be provided.
  • the light chain may have at least one heterologous T cell epitope therein.
  • the T cell epitope may be such that the light chain cannot take its native conformation when the nucleic acid is expressed.
  • the light chain may have any of the features described herein in respect of the heavy chain.
  • the invention also provides a nucleic acid encoding a recombinant light chain of an immunoglobulin molecule, wherein the light chain has at least one heterologous T cell epitope therein such that the light chain cannot take its native conformation when the nucleic acid is expressed.
  • the nucleic acid may include a non-specifc promoter.
  • Such nucleic acid(s) encode an immunoglobulin molecule, such as an antibody.
  • a nucleic acid which comprises a non-specific promoter and at least one sequence that encodes a recombinant immunoglobulin molecule, wherein the immunoglobulin molecule has at least one heterologous T cell epitope therein such that the immunoglobulin molecule cannot take its native conformation when the nucleic acid is expressed.
  • the recombinant immunoglobulin molecule, and heavy and light chains described above do not have any regulatory T cell epitopes.
  • the invention also provides:
  • a vaccine comprising a nucleic acid of the invention and an adjuvant
  • a pharmaceutical composition comprising a nucleic acid of the invention and a pharmaceutically acceptable carrier, excipient or diluent
  • nucleic acid of the invention for stimulating an immune response against at least one of the T cell epitope(s);
  • a method for stimulating an immune response against a T cell epitope comprising administering to a subject in need of such immune response a therapeutically effective amount of a nucleic acid of the invention.
  • antibodies such as monoclonal antibodies, which may be human or non-human, that have predetermined T cell epitopes cloned within their variable regions, so as to disrupt the primary antibody structure, inhibit folding and/or limit secretion to either just heavy chain or very low amounts of intact antibody, stimulate strong helper and antigen-specific T cell responses.
  • the inventors have also found that this effect can be achieved using nucleic acid encoding the heavy chain of such an antibody. It is believed that the T cell epitope is processed but not destroyed by the immunoproteosome.
  • the invention provides a DNA vaccine presenting pre-defined T cell epitopes within denatured immunoglobulin which enhances the frequency and the avidity of the T cell response.
  • the polypeptides encoded by the nucleic acids of the invention may be referred to herein as "Immunobodies”.
  • an immune response against a T cell epitope can be stimulated by a nucleic acid encoding at least the heavy chain of an immunoglobulin molecule into which the T cell epitope has been inserted such that the an immunoglobulin molecule cannot take its native conformation runs contrary to the expectations in the art, where it is taught that the antibody must be expressed in a functional form.
  • WO 96/19584 teaches that, where a nucleic acid encodes an antibody in which T cell epitopes are inserted into the CDRs of the antibody, the nucleic acid must encode a functional antibody.
  • EP0759944 describes a method of incorporating T cell epitopes within an antibody molecule that is secreted as an intact immunoglobulin protein.
  • US patent no. 7,067,1 10 discloses that an immune response can be raised against an antigen by a fusion protein of antibody and the antigen, the antibody is disclosed as lacking an immunoglobulin variable region.
  • this fusion protein will have regulatory T cell epitopes in the antigen.
  • the protein may stimulate an antibody response, it will not stimulate high avidity T cells responses due to regulatory T cell epitopes s in the antigen.
  • WO 00/64488 discloses a nucleic acid encoding a chimeric antibody having heterologous T cell epitopes inserted in the CDRs but not the variable region thereof, which nucleic acid is directed for expression in B cells.
  • the nucleic acid of the present invention is not directed for expression in B cells, and thus will not target B cells specifically either in vitro or in vivo.
  • the nucleic acid of the present invention can be taken up by any antigen presenting cells, including dendritic cells, and can therefore prime na ⁇ ve CTL and helper T cell responses, whereas the vaccine described in WO 00/64488 would only be useful in boosting pre-existing T cell responses.
  • the nucleic acids of the present invention have a non-specific promoter, i.e. a promoter that will promote expression of the nucleic acid but which has no specificity for cells in which expression is promoted.
  • the promoter preferably causes expression of the nucleic acid in dendritic cells and/or keratinocytes.
  • suitable promoters include the CMV promoter, the SV40 promoter, and other non-specific promoters known to those of skill in the art.
  • the nucleic acid of the present invention may have one or more promoters that cause specific expression in dendritic cells (e.g. Cd1 1 b promoter) and in keratinocytes (e.g. MHCII promoter, Chin et al., 2001 J. Immunol. 167, 5549-5557).
  • the nucleic acid of certain aspects of the invention encodes an immunoglobulin molecule, preferably an antibody that includes all of the major features of an antibody, that is to say heavy and light chains which include variable and constant regions.
  • the antibody may be monoclonal or polyclonal and may be IgA, IgD, IgE, IgG or IgM, although IgG is preferred.
  • the IgG antibody may be any IgG subclass, such as human IgGI , lgG2, lgG3 or lgG4, or mouse IgGI , lgG2a, lgG2b or lgG3.
  • the IgG antibody may be a human IgGI antibody having the lgG2 Fc binding domain.
  • the antibody may have the constant region of a human antibody, and the variable or hypervahable region of a mouse monoclonal antibody into which heterologous T cell epitopes have been inserted.
  • the variable region other than the hypervahable region may also be derived from the variable region of a human antibody.
  • Such an antibody is said to be humanised.
  • Methods for making humanised antibodies are known in the art. Methods are described, for example, in Winter, U.S. Patent No. 5,225,539.
  • the variable region of the antibody outside of the mouse hypervariable region may also be derived from a mouse monoclonal antibody. In such case, the entire variable region is derived from murine monoclonal antibody and the antibody is said to be chimerised.
  • the nucleic acid of certain aspects of the invention is such that the heavy chain, light chain or immunoglobulin molecule expressed therefrom has at least one heterologous T cell epitope therein so that the heavy chain, light chain or the immunoglobulin molecule cannot take its native conformation.
  • the T cell epitope may disrupt the expressed protein so that the heavy chain or the immunoglobulin molecule can no longer bind to its antigen, so that the heavy and light chains (where present) can no longer associate, or so that the heavy chain or immunoglobulin molecule cannot be secreted properly, for example.
  • the disruption may be in the tertiary structure of the immunoglobulin molecule which may prevent formation of the disulphide bonds.
  • the T cell epitope(s) may be inserted into or substituted for the CDR1 and CDR2 regions of the antibody.
  • CDR1 and CDR2 form part of the antibody ⁇ sheet conformation and are partially submerged within the folded molecule. Any change to their length, amino acid composition or charge will disrupt this structure and prevent heavy and light chain folding and association.
  • CDRH3 is exposed on the surface of the immunoglobulin molecule and is therefore more permissive of alterations. In the present invention, it is preferred if CDR1 and/ or CDR2 are substituted with T cell epitope(s).
  • loss of framework regions at the CDRH junctions completely disrupts antibody folding yet insertion of epitopes in these regions gives good T cell responses.
  • Incorporation of any epitope within the CDRH1 (5 amino acids in length) or CDRH2 (17 amino acids in length) causes sufficient disruption to allows secretion of heavy chain but only very low amounts of intact antibody, even if the light chain has its native sequence. This shows that the secondary structure is important for heavy and light chain pairing.
  • Incorporation of any epitope within CDRL1 of the light chain results in low level secretion of light chain, even if there is only a single epitope incorporated into the CDRH3 of the heavy chain.
  • Heterologous T cell epitope is intended to mean a T cell epitope which is heterologous to the antibody.
  • a heterologous T cell epitope may be one which was not previously present in the antibody.
  • the heterologous T cell epitope may be inserted as a whole, although it may be made up from an inserted amino acid sequence, together with flanking amino acids of the second portion. This is to ensure that the inserted epitope has a similar processing profile in the heterologous nucleic as from the original antigen.
  • One or more CTL/helper epitopes can be inserted within the same variable region.
  • the T cell epitope(s) can be inserted anywhere in the heavy chain or light chain. It is preferred if the or each epitope is inserted in the variable region of the heavy chain and/or light chain, although nucleic acids encoding heavy chains or antibodies having T cell epitopes inserted in just the constant region, or in the constant region and the variable region of a heavy chain and/or light chain are included within the invention. In the nucleic acids of the present invention, the sequence(s) encoding the T cell epitopes may be inserted into (i.e. added to) the sequence encoding the heavy chain and/or light chain, or may be substituted into the sequence encoding the heavy chain and/or light chain.
  • the T cell epitope(s) may be inserted in, or substituted for, any one or more the CDRs of the heavy and/or light chain, i.e. L1 , L2, L3, H1 , H2, or H3. Of these, L1 , H1 and H2 are currently preferred.
  • the T cell epitopes are inserted in, or substituted for, CDRL1 and/or H1 and/or H2.
  • the incorporated T cell epitopes are not of similar size and charge to the amino acids of the original CDR of the antibody so that the antibody does not take its native conformation, e.g. does not fold and is not secreted correctly.
  • they may be inserted in, or substituted for, the framework region surrounding the CDRs.
  • the inserted T cell epitopes are preferably cytotoxic T cell (CTL or CD8) epitopes.
  • CTL or CD8 epitopes cytotoxic T cell (CTL or CD8) epitopes.
  • helper T cell (CD4) epitopes may be inserted.
  • T cell epitopes can be predicted using known T cell algorithms or synthesised as peptides and screened using standard T cell assays.
  • the T cell epitopes may have an amino acid length in the range of from 5 to 50, 7 to 40, 8 to 30 or 9 to 20 amino acids, such as 9, 10, 11 , 12, 13, 14, 15, 16 , 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29 or 30 amino acids.
  • the epitopes may inserted using complementary oligonucleotides that encode the antigenic epitopes, which are annealed and cloned into specific sites of the antibody framework where CDR's (or other region) have been replaced with unique restriction enzyme sites.
  • CDR's or other region
  • one or a plurality of CD8 epitopes is/are inserted in, and/or substituted for, the CDR H1 and/or H2, or in the non-CDR variable region, of the heavy chain or the antibody.
  • one or a plurality of CD4 epitopes may be inserted in, and/or substituted for, the CDR L1 , or in the non-CDR variable region, of the light chain or the antibody.
  • T cell epitopes may be the same or different.
  • Nucleic acids of the present invention can incorporate multiple T cell epitopes from a single target antigen that can bind to the majority of both class I and class Il MHC molecules. This may create a vaccine that can be used in widespread population vaccination.
  • nucleic acids useful in the invention can incorporate multiple T cell epitopes from multiple target antigens that can bind to the most common class I and class Il phenotypes. This may create a vaccine that may prevent selection of antigen loss variants.
  • Target antigens may be from a single pathogen or tumour type or may be selected to give an immune response against a variety of pathogens or cancers.
  • Nucleic acids useful in the present invention targeting specific common HLA phenotypes may incorporate numerous T cell epitopes from a wide variety of cancers and/or pathogens, providing a single vaccine to prevent disease.
  • T cell epitope can be inserted, provided that it stimulates helper and/or cytotoxic T cell responses.
  • T cell epitopes from pathogens such as HIV, Hepatitis C and other infections that require CTLs to clear latent infections may be used, although it is preferred if the epitope is a "self-epitope", i.e. associated with a condition/disorder associated with cell proliferation such as cancer.
  • the T cell epitope is such that the heavy chain or antibody cannot fold correctly and be secreted. It is therefore preferred if the inserted epitopes are of not of similar size and amino acid composition to the original variable region.
  • the nucleic acid may have a plurality of different T cell epitopes so as to generate a wide variety of T cell responses.
  • the nucleic acid may incorporate multiple epitopes from a single antigen, thereby ensuring that the majority of individuals with different HLA types respond to the single vaccine.
  • multiple T cell epitopes from multiple antigens targeting a restricted spectrum of HLA types could be used.
  • the nucleic acid molecules of the invention may include a variety of antigens from a single pathogen or cancer type or they could include disparate antigens targeting a wide range of solid tumours or pathogens.
  • the nucleic acid molecules of the invention may even be designed to target different cell populations within a tumour, such as tumour epithelial and endothelial antigens.
  • T cell epitopes were inserted into structurally confined CDRs or non-CDR regions of the heavy chain, they gave superior CTL responses. This appears to be due to secretion of large amounts of heavy chain, which can only weakly associate with light chain due to the insertion of bulky epitopes into their variable regions. This is contrary to dogma, which states “that only proteins synthesised endogenously by antigen presenting cells are presented on MHC class I molecules and recognised by CTLs" - WO 96/19584. Uptake of exogenous antigen and presentation on MHC class I is a process known as cross presentation and usually requires uptake via specific receptors. This could be the CD64 receptor for human Fc ⁇ 1 antibodies.
  • the nucleic acid encoding the heavy chain preferably includes a leader sequence to allow it to be secreted.
  • the present inventors have found that, if the leader sequence of the heavy chain is removed to prevent secretion and allow more endogenous protein to be produced, this reduces the CTL response. This is completely contrary to expectations. Whilst not wishing to be bound by theory, the inventors believe that this implies that the nucleic acid is expressed in non-antigen presenting cells, which secrete high levels of heavy chain and low amounts of native protein which can then be taken up by antigen presenting cells.
  • the nucleic acid may directly transfect antigen presenting cells which migrate to the draining lymph node where they secrete low amounts of native protein and large amounts of heavy chain that is taken up by the same or adjacent antigen presenting cells and presented on MHC class I to na ⁇ ve CTLs. Therefore, for a nucleic acid vaccine to stimulate efficient CTL responses, it must preferably encode CTL epitopes within a protein that is secreted at very low levels and/or at the same time secretes large amounts of denatured protein. However, a CTL response cannot mature to a high affinity memory response in the absence of helper responses.
  • T helper epitopes are inserted into the heavy chain or the immunoglobulin molecule, preferably into the variable region of antibody light chains.
  • the nucleic acid of the present invention may or may not have a leader sequence for the light chain of the antibody.
  • nucleic acid is taken up by the antigen presenting cells which present the T helper epitopes in the context of MHC class Il from endogenously-synthesised protein, possibly by autophagy.
  • helper T cells to assist CTL responses, both the T cell epitopes they recognise must be presented on the same antigen presenting cells in a process known as linked T cell help. This implies that the antigen presenting cell synthesising the light chain, encoded by the nucleic acid, must either also synthesise, secrete and cross present the CTL epitopes themselves or take up heavy chain from an adjacent APC.
  • the present invention also provides isolated dendritic cells which present the heterologous helper T cell epitopes on MHC class Il from endogenously- produced light chain and heterologous CTL epitopes from cross-presented heavy chain. Such dendritic cells may be used in the therapies described herein.
  • Nucleic acids of the present invention can make existing T cell epitopes more immunogenic by encoding a denatured antibody which leads to an increase in both the frequency and avidity of T cell responses.
  • the nucleic acid of the invention may be DNA, cDNA, or RNA such as mRNA, obtained by cloning or produced wholly or partly by chemical synthesis.
  • the nucleic acid is preferably in a form capable of being expressed in the subject to be treated.
  • nucleic acid of the present invention may be recombinant or provided as an isolate, in isolated and/or purified form. It may be free or substantially free of nucleic acid flanking the gene in the human genome, except possibly one or more regulatory sequence(s) for expression.
  • nucleic acid according to the invention includes RNA
  • reference to the sequences shown herein should be construed as reference to the RNA equivalent, with U substituted for T.
  • Nucleic acids of the present invention can be readily prepared by the skilled person, for example using the information and references contained herein and techniques known in the art (for example, see Sambrook, Fritsch and Maniatis, "Molecular Cloning", A Laboratory Manual, Cold Spring Harbor Laboratory Press, 1989, and Ausubel et al, Short Protocols in Molecular
  • DNA encoding the polypeptide may be generated and used in any suitable way known to those of skill in the art, including by taking encoding DNA, identifying suitable restriction enzyme recognition sites either side of the portion to be expressed, and cutting out said portion from the DNA. The portion may then be operably linked to a suitable promoter in a standard commercially available expression system.
  • Another recombinant approach is to amplify the relevant portion of the DNA with suitable PCR primers. Modifications to the sequences can be made, e.g. using site directed mutagenesis, to lead to the expression of modified peptide or to take account of codon preferences in the host cells used to express the nucleic acid.
  • the sequences can be incorporated into a vector having one or more control sequences operably linked to the nucleic acid to control its expression.
  • the vectors may include other sequences such as promoters or enhancers to drive the expression of the inserted nucleic acid, nucleic acid sequences so that the polypeptide is produced as a fusion and/or nucleic acid encoding secretion signals so that the polypeptide produced in the host cell is secreted from the cell.
  • polypeptide can then be obtained by transforming the vectors into host cells in which the vector is functional, cultuhng the host cells so that the polypeptide is produced and recovering the polypeptide from the host cells or the surrounding medium.
  • Prokaryotic and eukaryotic cells are used for this purpose in the art, including strains of E. coli, yeast, and eukaryotic cells such as insect cells, and animal cells, for example, COS, CHO cells, Bowes Melanoma and other suitable human cells.
  • the present invention relates to nucleic acid(s) encoding the heavy and light chains of an antibody, the respective nucleic acids may be present in the same expression vector, driven by the same or different promoters, or in separate expression vectors.
  • the nucleic acids of the present invention may be used to stimulate an immune response against at least one of the T cell epitope(s) in a patient such as a mammal, including human. Helper and/or cytotoxic T cell responses may be stimulated.
  • the T cell response against a particular epitope obtained by the present invention may have a higher avidity than that obtained by immunisation with the same epitope as a simple peptide, or by immunisation with the same epitope encoded within an antigen either as a peptide or a nucleic acid.
  • the nucleic acids of the invention may be administered as a combination therapy, i.e. a nucleic acid encoding the light chain and nucleic acid encoding the heavy chain.
  • the nucleic acid may be administered intravenously, intradermal ⁇ , intramuscularly, orally or by other routes. Intradermal or intramuscular administration is preferred because these tissues contain dendritic cells
  • the term "treatment” includes any regime that can benefit a human or non-human animal.
  • the treatment may be of an inherited or acquired disease.
  • the treatment is of a condition/disorder associated with cell proliferation such as cancer or of infectious disease.
  • types of cancer that can be treated with the nucleic acid include any solid tumour, colorectal cancer, lung, breast, gastric, ovarian, uterine, liver, kidney, pancreatic, melanoma, bladder, head and neck, brain, oesophageal, pancreatic, and bone tumours, as well as soft tissue cancers, and leukaemias.
  • infectious diseases that can be treated with the nucleic acid include infection with HIV, Hepatitis C, or any chronic infection that requires T cell immunity for clearance.
  • the nucleic acid may be employed in combination with a pharmaceutically acceptable carrier or carriers.
  • Such carriers may include, but are not limited to, saline, buffered saline, dextrose, liposomes, water, glycerol, ethanol and combinations thereof.
  • Adjuvants may be employed to facilitate stimulation of the host's immune response, and may include, aluminium hydroxide, lysolecithin, pluronic, polyols, polyanions, peptides, proteins and oil emulsions.
  • the nucleic acids useful in the invention can be formulated in pharmaceutical compositions. These compositions may comprise, in addition to one of the above substances, a pharmaceutically acceptable excipient, carrier, buffer, stabiliser or other materials well known to those skilled in the art. Such materials should be non-toxic and should not interfere with the efficacy of the active ingredient.
  • the precise nature of the carrier or other material may depend on the route of administration, e.g. intradermal, oral, intravenous, cutaneous or subcutaneous, nasal, intramuscular, intraperitoneal routes.
  • the formulation is preferably nucleic acid as a stable dry powder precipitated onto the surface of microscopic gold particles and suitable for injection via a gene gun.
  • the formulation may be suitable for intradermal or intramuscular administration using electroporation.
  • compositions comprising, or for the delivery of, nucleic acids are preferably administered to an individual in a "therapeutically effective amount", this being sufficient to show benefit to the individual.
  • the actual amount administered, and rate and time-course of administration, will depend on the nature and severity of what is being treated. Prescription of treatment, e.g. decisions on dosage etc, is within the responsibility of general practitioners and other medical doctors, and typically takes account of the disorder to be treated, the condition of the individual patient, the site of delivery, the method of administration and other factors known to practitioners.
  • the nucleic acids of the invention are particularly relevant to the treatment of existing cancer and in the prevention of the recurrence of cancer after initial treatment or surgery. Examples of the techniques and protocols mentioned above can be found in Remington's Pharmaceutical Sciences, 16 th edition, Oslo, A. (ed), 1980.
  • the nucleic acid of the invention stimulate helper and/or cytotoxic T cells that can significantly inhibit the growth of tumour cells when administered to a human in an effective amount.
  • the optimal dose can be determined by physicians based on a number of parameters including, for example, age, sex, weight, severity of the condition being treated, the active ingredient being administered and the route of administration. For example, a dose of 1 - 1000 ⁇ g of DNA is sufficient to stimulate both helper and cytotoxic T cell responses.
  • the nucleic acids of the invention may be administered along with additional pharmaceutically acceptable ingredients.
  • additional pharmaceutically acceptable ingredients include, for example, immune system stimulators.
  • a composition may be administered alone or in combination with other treatments, either simultaneously or sequentially dependent upon the condition to be treated.
  • Other cancer treatments include other monoclonal antibodies, other chemotherapeutic agents, other radiotherapy techniques or other immunotherapy known in the art.
  • One particular application of the compositions of the invention are as an adjunct to surgery, i.e. to help to reduce the risk of cancer reoccurhng after a tumour is removed.
  • Injections (id) may be the primary route for therapeutic administration of the nucleic acid of this invention.
  • the nucleic acids may be administered in a localised manner to a tumour site or other desired site or may be delivered in a manner in which it targets tumour or other cells.
  • the dose of nucleic acid will be dependent upon the properties of the agent employed, e.g. its binding activity and in vivo plasma half-life, the concentration of the polypeptide in the formulation, the administration route, the site and rate of dosage, the clinical tolerance of the patient involved, the pathological condition afflicting the patient and the like, as is well within the skill of the physician.
  • doses of 100 ⁇ g of nucleic acid per patient per administration are preferred, although dosages may range from about 10 ⁇ g to 1 mg per dose. Different dosages are utilised during a series of sequential inoculations; the practitioner may administer an initial inoculation and then boost with relatively smaller doses of nucleic acid.
  • the present invention relates to a method of engineering T cell epitopes from target antigens into the variable regions of antibodies, and the use of such engineered antibodies as vaccines to stimulate both helper and cytotoxic T cell responses.
  • a further aspect of the present invention provides a host cell containing a nucleic acid as disclosed herein.
  • the nucleic acid of the invention may be integrated into the genome (e.g. chromosome) of the host cell. Integration may be promoted by inclusion of sequences that promote recombination with the genome in accordance with standard techniques.
  • the nucleic acid may be on an extra-chromosomal vector within the cell, or otherwise identifiably heterologous or foreign to the cell.
  • a still further aspect provides a method, which comprises introducing the nucleic acid of the invention into a host cell.
  • the introduction which may (particularly for in vitro introduction) be generally referred to without limitation as "transformation", may employ any available technique.
  • suitable techniques may include calcium phosphate transfection, DEAE- Dextran, electroporation, liposome-mediated transfection and transduction using retrovirus or other virus, e.g. vaccinia or, for insect cells, baculovirus.
  • suitable techniques may include calcium chloride transformation, electroporation and transfection using bacteriophage.
  • direct injection of the nucleic acid could be employed.
  • Marker genes such as antibiotic resistance or sensitivity genes may be used in identifying clones containing nucleic acid of interest, as is well known in the art.
  • the introduction may be followed by causing or allowing expression from the nucleic acid, e.g. by culturing host cells (which may include cells actually transformed although more likely the cells will be descendants of the transformed cells) under conditions for expression of the gene, so that the encoded polypeptide (or peptide) is produced. If the polypeptide is expressed coupled to an appropriate signal leader peptide it may be secreted from the cell into the culture medium.
  • a polypeptide or peptide may be isolated and/or purified from the host cell and/or culture medium, as the case may be, and subsequently used as desired, e.g. in the formulation of a composition which may include one or more additional components, such as a pharmaceutical composition which includes one or more pharmaceutically acceptable excipients, vehicles or carriers (e.g. see below).
  • the present inventon also provides a method for identifying T cell epitopes in a candidate antigen, comprising: depleting T regulatory cells in a non-human animal; immunising the non-human animal with a candidate antigen; and screening to see whether a T cell response is raised against either peptides to predicted epitopes in the candidate antigen or all the possible overlapping peptides within the candidate antigen.
  • the method may be carried out in a non-human animal, such as a mouse or a rat.
  • T regulatory cells can be depleted in the non-human animal using anti- CD25 antibodies, which optionally may be conjugated with toxins such as Ontak, or by chemotherapy such as cyclophosphamide which preferentially kills T regulatory cells.
  • the non-human animal may be immunised with DNA encoding the candidate antigen, or by the candidate antigen itself. It is preferred that the candidate antigen is provided as an antigen-Fc fusion protein.
  • the peptide against which any T cell response stimulated in the non-human animal is identified. This can be done in vitro using a technique such as ELISPOT.
  • this epitope can be used to immunise a non-human animal. If this peptide elicits a T cell response, the avidity and frequency can be enhanced by encoding the epitope within a nucleic acid in accordance with the present invention. This method can allow the identification of T cell epitopes that are processed by the immunoproteosome.
  • FIG. 1 Map depicting features of the heavy chain vector pOhgHIB
  • the wild type de-immunised heavy variable region of antibody SC100 was cloned using Hindlll/Afel inframe with the human IgGI Fc constant region.
  • the Fc region comprises the CH1 , CH2, CH3 domains and the hinge region.
  • High-level expression in mammalian cells is driven from the human cytomegalovirus immediate early promoter.
  • EM7 is a bacterial promoter that controls expression of the zeocin resistance gene allowing antibiotic selection in E.coli while the SV40 early promoter upstream of the resistance gene allows selection in mammalian cells.
  • the vector also contains within its backbone the CoIEI origin of replication for propagation in bacteria. Complimentary determining DNA sequences were effectively removed and exchanged for restriction sites RE1 , RE2 and RE3 (Fspl, Msc ⁇ and Srf I respectively) singly and in combination.
  • FIG. 2 Map depicting features of the heavy chain vector pOhgLIB
  • the wild type de-immunised light variable region of antibody SC100 was cloned using BamHI/BsiWI inframe with the human kappa constant region. High-level expression in mammalian cells is driven from the human cytomegalovirus immediate early promoter. BGH polyadenylation signals downstream of the Orig LIB chain to ensure mRNA stability and effective termination.
  • the vector also includes the CoIEI origin of replication and the antibiotic resistance gene for ampicillin allowing propagation and selection in bacteria. Complimentary determining regions were effectively removed and exchanged for restriction sites RE4, RE5 and RE6 (EcoRV, Ssp I and Hpa I respectively) singly and in combination.
  • Figure 3 Sequence of the wild type lmmunobody chimeric heavy chain.
  • Nucleotide and on translation amino acid sequence are illustrated for the full length chimeric igG1 heavy chain. Locations of CDR's are within boxes defined by the kabat numbering scheme. The stop codon is depicted by a red astrix. The Hin ⁇ WUAfe I restriction sites are highlighted utilised in transfer of the variable heavy region.
  • Figure 4 Sequence of the wild type lmmunobody chimeric kappa chain Nucleotide and on translation amino acid sequence are illustrated for the full length chimeric kappa chain. Locations of CDR's are within boxes defined by the kabat numbering scheme. The stop codon is depicted by an asterisk. The SamHI/Ss/WI restriction sites utilised in transfer of the variable light region are highlighted.
  • Figure 5 Overlapping extension PCR
  • the forward primers H1 , H2. H3, L1 , L2 and L3 were designed to replace CDR1 , 2 and 3 within the heavy and light chain variable region respectively.
  • Each primer contained, centrally located, the chosen unique enzyme recognition sequence devoid of the CDR sequence to be removed (green section) and flanked by 10-20bp of wild type sequence.
  • the forward primers were used in a first round of PCR in conjunction with a general reverse primer, huHeClonR or huLiClonR (Table 2), that anneals to the human heavy and light constant domains within the wild type constructs pOrigHIB and pOrigLIB respectively.
  • the fragment generated does not contain wild type CDR sequence (red section), but is effectively exchanged for the restriction site.
  • a second round of PCR is required using the PCR product generated from the first round as a reverse primer with the general CMV forward primer that anneals to the CMV promoter within the single plasmids.
  • Second round PCR products were subcloned into pCR2.1 (Invitrogen) and, after sequence confirmation, the heavy/light (VH and VL) variable regions containing H1 , H2, H3, L1 , L2 and L3 versions singly, in combination and together were inserted back into the single constructs pOrigHIB and pOrigLIB, exchanging the wild type regions using Hindlll/Afel and BamHI/BsiWI respectively.
  • FIG. 6 Sequence of the ImmunoBody heavy chain variable region Nucleotide and amino acid sequence of the heavy variable region
  • CDR's have been replaced with their corresponding enzyme site H1 , H2 and H3, singly in combination and together.
  • the unique restriction enzyme sites are highlighted.
  • CDR1 , 2 and 3 were replaced with Fsp ⁇ , Msc ⁇ and Srf ⁇ respectively.
  • Figure 7 Sequence of the ImmunoBody kappa chain variable region Nucleotide and amino acid sequence of the heavy variable region where CDR's have been replaced with their corresponding enzyme site L1 , L2 and L3, singly in combination and together.
  • the unique restriction enzyme sites are highlighted.
  • CDR1 , 2 and 3 were replaced with EcoRV, Ssp ⁇ and Hpa ⁇ respectively.
  • Figure 8 Map depicting features of the double expression vector pDCOrig Once all epitopes have been incorporated into the variable heavy and variable light sites within the single vectors, they are transferred into the double expression vector utilising as highlighted Hindlll/Afel and BamHI/BsiWI in frame with their respective human constant regions.
  • the Fc region of the heavy chain comprises of the CH1 , CH2, CH3 domains and the hinge region. High-level expression of both the heavy and light chains in mammalian cells is driven from the human cytomegalovirus immediate early promoter. BGH polyadenylation signals downstream of both chains to ensure mRNA stability and effective termination.
  • EM7 is a bacterial promoter that controls expression of the zeocin resistance gene allowing antibiotic selection in E.coli while the SV40 early promoter upstream of the resistance gene allows selection in mammalian cells. SV40 polyadenylation signals downstream of the resistance gene in order to direct proper processing of the 3'end of the zeo r mRNA.
  • the vector also contains within its backbone the CoIEI origin of replication for propagation in bacteria.
  • Figure 10 Nucleotide and amino acid sequence of the DCIB15 heavy variable region without a leader.
  • the leader was removed by PCR using the forward primer pOrig heavy no leader with the reverse primer huHeClonR (Table 2) that binds to the human IgGI CH1 domain effectively re amplifying the heavy variable (V H ) region.
  • V H region minus leader was cloned back into the double expression construct DCIB15 using Hindlll/Afel inframe with the human IgGI constant region. Amino acids within boxes represent the GP100210M epitope in H1 (Tl M DQVP FSV) and the TRP2 epitope in H2 (SVYDFFVWL).
  • the Hindl ⁇ /Afe I restriction sites utilised in transfer of the variable heavy region are highlighted.
  • Figure 11 Nucleotide and amino acid sequence of the DCIB15 kappa variable region without a leader
  • the leader was removed by PCR using the forward primer pOrig light no leader with the reverse primer huLiClonR (Table 2) re amplifying the light variable (V L ) region.
  • V L region minus leader was cloned back into the double expression construct DCIB15 using SamHI/Ss/WI in frame with the human kappa constant region. Amino acids within boxes represent the HepB CD4 epitope in L1 (TPPAYRPPNAPIL).
  • the BamH ⁇ /BsiWI ⁇ restriction sites are highlighted utilised in transfer of the variable light region.
  • Figure 12 Sequence of human lgG2 constant region Nucleotide and amino acid sequence of the heavy human lgG2 constant region amplified. The Afe ⁇ and Sap ⁇ restriction sites are highlighted utilised in transfer and replacement of the huigGI constant region in the double expression vector DCIB15.
  • Figure 13 Sequence of human igG3 constant region Nucleotide and amino acid sequence of the heavy human igG2 constant region amplified. The Afe ⁇ and Sap ⁇ restriction sites are highlighted utilised in transfer and replacement of the huigGI constant region in the double expression vector DCIB15
  • Figure 14 Human isotypes of the immunobody double expression vector A Map of the double expression vector pDC0hglB15 huigG2. B Map of the double expression vector pDC0hglB15huigG3. The HindWUAfe I and SamHI/Ss/WI restriction sites utilised in transfer of the variable heavy and light region are highlighted.
  • Figure 15 Sequence of DCIB66 heavy chain containing the G2 motif Nucleotide and amino acid sequence of the chimeric heavy chain.
  • the amino acids E233 L234 L235 within a critical binding motif for interaction with the high affinity Fc ⁇ R1 (CD64) were substituted with P233 V234 A235 from human igG2 highlighted in bold within a box.
  • Other amino acids within boxes represent the GP100210M epitope in H1 (TIMDQVPFSV) and the TRP2 epitope in H2 (SVYDFFVWL).
  • the Age ⁇ /Ahd ⁇ sites highlighted were used in transfer of the section containing the substitutions into pDCOhglB15 huigGI .
  • the Hind ⁇ /Afe I restriction sites utilised in transfer of the variable heavy region are depicted in bold.
  • Figure 16 Sequence of DCIB67 heavy chain containing the G1 binding motif Nucleotide and amino acid sequence of the chimeric heavy chain.
  • the amino acids P233 V234 A235 within the human lgG2 constant region were substituted with the critical binding motif for interaction with the high affinity Fc ⁇ R1 (CD64) E233 L234 L235 G236 from human IgGI highlighted in bold within a box.
  • Other amino acids within boxes represent the GP10021 OM epitope in H1 (TIMDQVPFSV) and the TRP2 epitope in H2 (SVYDFFVWL).
  • the Age ⁇ /Ahd ⁇ sites highlighted were used in transfer of the section containing the substitutions into pDC0hglB15 huigG2.
  • the HindWUAfe I restriction sites utilised in transfer of the variable heavy region are depicted in bold.
  • Figure 17 Murine lgG2a lmmunobody expression vectors
  • Figure 18 Schematic diagram to depict construction of the regulatory compliant plasmid pVAXDCIB54
  • the heavy single chain vector pVaxlB54 HIB (A) was linearised using Nrul.
  • the light chain expression cassette from pOrigLIB (B) was excised using Nrul and Hpal and cloned into the linearised plasmid to generate the double expression vector pVaxDCIB54 (C).
  • the Hinc ⁇ W/Afe I and BamH ⁇ /Bsi ⁇ N ⁇ restriction sites utilised in transfer of the variable heavy and light region are highlighted.
  • Figure 19 Sequence of DCIB15 Nucleotide and amino acid sequence of the heavy and light variable regions cloned in frame with the human IgGI Fc and kappa constant regions within the expression vector pDCOrig. Amino acids within boxes represent the GP100210M epitope in H1 (TIMDQVPFSV), the TRP2 epitope in H2 (SVYDFFVWL) and the HepB CD4 epitope in L1 (TPPAYRPPNAPIL). The Hind ⁇ /Afe I and SamHI/Ss/WI restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • Figure 20 ImmunoBody constructs produce low levels of intact protein.
  • DCIB48, DCIB49, DCIB52, DCIB54 by sandwich Elisa. Plates were coated with an anti-human Fc specific antibody or anti-human kappa chain antibody. To detect heavy chain an anti-human IgG Fc specific HRP antibody was used in combination with the anti-human Fc specific coating antibody. To detect intact ImmunoBody an anti-human kappa chain specific HRP antibody was used in combination with anti-human Fc specific coating antibody. To detect light chain anti-human kappa chain specific HRP antibody was used in combination with the anti-human kappa chain specific antibody.
  • Figure 24 Sequence of DCIB32 Nucleotide and amino acid sequence of the heavy and light variable regions cloned inframe with the human IgGI Fc and kappa constant regions within the expression vector pDCOrig. Amino acids within boxes represent the TRP2 epitope (SVYDFFVWL) in H3 and the HepB CD4 epitope in L3 (TPPAYRPPNAPIL). The HindUVAfe I and ⁇ amHI/ ⁇ s/WI restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • Figure 26 Sequence of DCIB48 Nucleotide and amino acid sequence of the heavy and light variable regions cloned inframe with the human IgGI Fc and kappa constant regions within the expression vector pDCOrig. Amino acids within boxes represent the TRP2 epitope (SVYDFFVWL) in H2 and the HLA-DR4 restricted gp100 CD4 epitope in H3 (WNRQLYPEWTEAQRLD). The HindlW/Afe I and ⁇ amHI/ ⁇ s/WI restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • Figure 31 CTL epitopes incorporated into ImmunoBody framework are processed and presented to elicit an immune response in vivo.
  • mice were immunised on days 0, 7, and 14 with an ImmunoBody construct containing the TRP2 epitope in CDR H2 and HepB CD4 epitope in
  • CDR L1 (DCIB18).
  • splenocytes were analysed by I FN ⁇ elispot assay against TRP2 peptide, HepB helper peptide and a media control. Responses are measured as spots/million splenocytes.
  • Splenocytes from immunised mice were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • C splenocytes from immunised mice were depleted of CD8 T cells and analysed against TRP2 peptide, HepB helper peptide and a media control for the presence epitope specific responses in I FN ⁇ elispot assay. Responses are measured as spots/million splenocytes.
  • D cytotoxicity of splenocytes from immunised mice in a 4 hour 51 Cr-release assay against the B16F10, B16F10 IFN ⁇ and B16F10 siKb melanoma cell lines after 6 days in vitro TRP2 peptide stimulation.
  • mice were immunised on days 0, 7, and 14 with lmmunoBody DNA (DCIB15, DCIB31 , DCIB32, DCIB36, DCIB48,
  • DCIB52 and DCIB54 were analysed by IFN ⁇ elispot assay against TRP2 peptide and a media control. Responses are measured as spots/million splenocytes.
  • Splenocytes from immunised mice were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • mice were immunised on days 0, 7, and 14 with lmmunoBody DNA (DCIB15, DCIB48, DCIB49, DCIB52 and DCIB54).
  • splenocytes were analysed by IFN ⁇ elispot assay against HepB helper peptide (DCIB15, DCIB49 and DCIB52) or gp100DR4 helper peptide (DCIB48 and DCIB54) and a media control. Responses are measured as spots/million splenocytes.
  • ImmunoBody DNA immunisation (DCIB18) was compared to s.c. immunisation with peptide epitope in Incomplete Freund adjuvant or immunisation with a DNA expressing the TRP2 antigen.
  • C57BI/6 mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide ( ⁇ ), HepB helper peptide (; ) and a media control (D). Responses are measured as spots/million splenocytes.
  • Splenocytes from ImmunoBody DNA (0) and peptide ( ⁇ ) immunised mice were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • D ImmunoBody DNA immunisation (DCIB18) was compared to immunisation with TRP2 peptide pulsed DCs.
  • C57BI/6 mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were analysed by IFN ⁇ elispot assay against titrating quantities of TRP2 peptide. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • ImmunoBody DNA immunisation was compared to immunisation with TRP2 peptide pulsed DCs.
  • C57BI/6 mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were stimulated in vitro with TRP2 peptide pulsed LPS blasts.
  • Six days post stimulation CTL lines were assessed by chromium release assay for ability to lyse B16F10 or B16F10 siKb melanoma lines. Responses are measured as % cytotoxicity.
  • ImmunoBody DNA immunisation was compared to immunisation with SIINFEKL peptide.
  • C57BI/6 mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were analysed by IFN ⁇ elispot assay against SIINFEKL peptide and a control peptide. Responses are measured as spots/million splenocytes.
  • ImmunoBody DNA immunisation was compared to immunisation with gp100 210M peptide.
  • HHDII mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were analysed by IFN ⁇ elispot assay against titrating quantities of gp100 210M peptide and a control. Responses are measured as spots/million splenocytes.
  • ImmunoBody DNA immunisation was compared to immunisation with SIINFEKL peptide.
  • C57BI/6 mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were analysed by IFN ⁇ elispot assay against titrating quantities of SIINFEKL peptide. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • ImmunoBody DNA immunisation (DCIB15) was compared to immunisation with gp100 210M peptide.
  • HHDII mice were immunised on days 0, 7, and 14 and on day 19 splenocytes were analysed by IFN ⁇ elispot assay against titrating quantities of gp100 210M peptide. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • FIG. 34 Multiple epitopes can be processed from CDR H2 site.
  • A C57BI/6 mice were immunised on days 0, 7 and 14 with ImmunoBody construct containing SIINFEKL epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB24).
  • splenocytes were analysed in IFN ⁇ elispot assay against SIINFEKL peptide, an irrelevant peptide, HepB CD4 peptide and media control. Responses are measured as spots/million splenocytes.
  • FIG. 37 Multiple CTL epitopes can be processed from the variable region.
  • A HHDII mice were immunised on days 0, 7 and 14 with ImmunoBody construct containing gp100 IMDQVPFSV epitope in CDR H1 with removal of part of the framework and HepB CD4 epitope in CDR L1 (DCIB17).
  • splenocytes were analysed in IFN ⁇ elispot assay against gp100 IMDQVPFSV peptide, HepB CD4 peptide and media control. Responses are measured as spots/million splenocytes.
  • HHDII mice were immunised on days 0, 7 and 14 with ImmunoBody construct containing Tie2 epitope in CDR H1 with removal of part of the framework and HepB CD4 epitope in CDR L1 (DCIB26).
  • ImmunoBody construct containing Tie2 epitope in CDR H1 with removal of part of the framework and HepB CD4 epitope in CDR L1 (DCIB26).
  • splenocytes were analysed in IFN ⁇ elispot assay against Tie2 peptide, HepB CD4 peptide and media control. Responses are measured as spots/million splenocytes.
  • Figure 38 Multiple CTL responses can be generated from different epitopes within the same ImmunoBody construct.
  • HLA-A2 restricted gp100 epitope IMDQVPFSV was engineered into the CDR H1 site alongside the TRP2 epitope SVYDFFVWL in CDR H2 and the HepB CD4 epitope was present in the CDR L1 site (DCIB15).
  • HHDII mice were immunised on days O, 7, and 14 with ImmunoBody DNA. On day 19 splenocytes were analysed by IFN ⁇ elispot assay against gp100 peptide, TRP2 peptide, HepB helper peptide and a media control. Responses are measured as spots/million splenocytes.
  • B Splenocytes from immunised mice were assayed for avidity to the gp100 modified IMDQVPFSV ( ⁇ ) epitope, gp100 wt ITDQVPFSV epitope (A) and TRP2 epitope ( ⁇ ) by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • HHDII mice were immunised on days 0, 7, and 14 with ImmunoBody DNA containing either i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and
  • HepB CD4 epitope in CDR L1 (DCIB15) or ii) TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB18).
  • splenocytes were analysed by IFN ⁇ elispot assay against gp100 peptide ( ⁇ ), TRP2 peptide (J), HepB helper peptide (; ) and a media control (D). Responses are measured as spots/million splenocytes.
  • mice C57BI/6 mice were immunised i.m. with 10 ⁇ g DNA solution combined with electroporation. Immunisations were performed three times at weekly intervals in the tibialis muscle. Mice were immunised with DCIB24 or DCIB18 alone, both combined in the same site or with both at the same time but in separate sites. On day 19 splenocytes were analysed for the presence of TRP2,
  • SIINFEKL peptide specific immune responses Responses are measured as spots/million splenocytes.
  • Figure 39 Sequence of DCIB37
  • Figure 42 Sequence of DCIB42 Nucleotide and amino acid sequence of the heavy and light variable regions cloned in frame with the human IgGI Fc and kappa constant regions within the expression vector pDCOrig. Amino acids within boxes represent the GP100 F7Y epitope in H1 (TITDQVPYSV) and the HepB CD4 epitope in L1 (TPPAYRPPNAPIL). The HindW/Afe I and ⁇ amHI/ ⁇ s/WI restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • Figure 44 Modification at non-anchor residues can enhance epitope immunogenicity.
  • HHDII mice were immunised at days 0, 7 and 14 with ImmunoBody constructs containing modified gp100 epitopes in the CDR H1 region (DCIB37, DCIB40, DCIB41 , DCIB42 and DCIB43).
  • splenocytes were analysed by IFN ⁇ elispot assay against gp100 wild type epitope peptide and a media control. Responses are measured as spots/million splenocytes.
  • Figure 46 Multiple CD4 helper responses can be processed and presented to elicit an immune response in vivo.
  • mice were immunised at days 0, 7 and 14 with ImmunoBody constructs containing the I-Ab restricted HepB CD4 epitope in the CDR L1 region (DCIB15).
  • mice were immunised at days 0, 7 and 14 with ImmunoBody constructs containing the I-Ad restricted Flu HA CD4 epitope in the CDR L1 region (DCIB21 ).
  • HLA-DR4 transgenic mice were immunised at days 0, 7 and 14 with ImmunoBody constructs containing the HLA-DR4 restricted gp100 CD4 epitope in the CDR L1 (DCIB35).
  • splenocytes were analysed by IFN ⁇ elispot assay against corresponding peptide, an irrelevant peptide and a media control. Responses are measured as spots/million splenocytes.
  • HLA-DR4 transgenic mice were immunised at days 0, 7 and 14 with ImmunoBody constructs containing the HLA-DR4 restricted gp100 CD4 epitope in the CDR L1 (DCIB35), in the CDR H3 (DCIB54) and in the CDR L3 (DCIB50).
  • splenocytes were analysed by IFN ⁇ elispot assay against corresponding peptide, an irrelevant peptide and a media control. Responses are measured as spots/million splenocytes.
  • HHDII mice were immunised at day O, 7 and 14 with ImmunoBody DNA constructs containing i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB15), ii) gp100 epitope in CDR H1 ,
  • TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 without the leader sequence on the heavy chain iii) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 without the leader sequence on the light chain.
  • splenocytes were analysed by IFN ⁇ elispot assay against gp100 ( ⁇ ) and HepB CD4 (j ) peptides and a media control (D). Responses are measured as spots/million splenocytes.
  • C, C57BI/6 mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB15), ii) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 without the leader sequence on the heavy chain.
  • splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide. Responses are measured as spots/million splenocytes.
  • C57BI/6 mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB15), ii) gp100 epitope in CDR H1 ,
  • splenocytes were analysed by IFN ⁇ elispot assay against HepB helper peptide. Responses are measured as spots/million splenocytes.
  • C57BI/6 mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB15), ii) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 lacking the Fc region.
  • ImmunoBody DNA constructs containing i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB15), ii) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 lacking the Fc region.
  • splenocytes were analysed by I FN ⁇ elispot assay against TRP2 (J) peptide, a media control (D), the B16F10 melanoma line ( ⁇ ) and the B16F10 siKb negative control cell line (; ). Responses are measured as spots/million splenocytes.
  • mice C57BI/6 mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing i) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 (DCIB15), ii) gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and HepB CD4 epitope in CDR L1 lacking the Fc region.
  • splenocytes were analysed by I FN ⁇ elispot assay against TRP2 peptide. Responses are measured as spots/million splenocytes.
  • C The same mice were analysed for responses specific for the HepB helper peptide. Responses are measured as spots/million splenocytes.
  • D Splenocytes from mice immunised with DCIB15 or DCIB15 lacking the Fc region (DCIB15 FcStop) were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in I FN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide ( ⁇ ), a media control (D) and the HepB helper peptide (; ). Responses are measured as spots/million splenocytes.
  • F Determination of heavy chain, light chain and intact ImmunoBody from supernatant of CHO-S transfectants (DCIB15, DCIB33, DCIB65, DCIB66 and DCIB67) by sandwich Elisa. Plates were coated with an anti-human Fc specific antibody or anti-human kappa chain antibody. To detect heavy chain an anti-human IgG Fc specific HRP antibody was used in combination with the anti-human Fc specific coating antibody.
  • an anti-human kappa chain specific HRP antibody was used in combination with anti-human Fc specific coating antibody.
  • To detect light chain anti-human kappa chain specific HRP antibody was used in combination with the anti- human kappa chain specific antibody.
  • G Determination of heavy chain ImmunoBody from supernatant of CHO-S transfected with DCIB53 by sandwich Elisa. Plates were coated with an anti- mouse Fc specific antibody.
  • an anti-mouse lgG2a specific HRP antibody was used.
  • FIG. 50 ImmunoBody immunisation enhances immune responses and overcomes regulation observed from whole antigen.
  • HLA-A2 transgenic mice HHDII
  • ImmunoBody DNA constructs DCIB15 or whole gp100 antigen in pcDNA3 vector.
  • splenocytes were analysed by IFN ⁇ elispot assay against gp100 peptide or control. Responses are measured as spots/million splenocytes.
  • C57BI/6 mice were depleted of CD25 positive cells by injection of anti-CD25 antibody (PC61 ) 400 ⁇ g i.p. Both CD25 depleted mice and undepleted animals were subsequently immunised at day 4, 11 and 18 with ImmunoBody DNA constructs DCIB15 or whole TRP2 antigen in pOrig vector. On day 23, splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide or control. Responses are measured as spots/million splenocytes.
  • C and D HHDII mice were either untreated (c) or treated with 400 ⁇ g PC61 mAb i.p., (d).
  • mice were immunised with 100 ⁇ g Z12 peptide and 100 ⁇ g Z48 peptide, mixed 1 :1 in IFA (s.c).
  • Repeat peptide immunisations were administered 7 days after the first peptide immunisation.
  • Splenocytes were harvested 14 days after the final immunisation and restimulated with 1 ⁇ g/ml Z12 peptide (black bars) or media alone (open bars) in an IFN ⁇ ELIspot assay. Bars indicate the mean of triplicate values with error bars representing the standard deviation from the mean.
  • G HHDII mice were immunised with 100 ⁇ g Z12 peptide mixed 1 :1 in IFA (s.c).
  • peptide immunisations were administered at days 7 and 14 days after the first peptide immunisation.
  • Splenocytes were harvested 7 days after the final immunisation and analysed for the presence of epitope specific responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured from individual mice as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • H, HHDII mice were immunised with ImmunoBody DNA construe DCIB71 via gene gun at days 0, 7 and 14. Splenocytes were harvested 7 days after the final immunisation and analysed for the presence of epitope specific responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured from individual mice as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • Figure 51 Sequence of DCIB71
  • Figure 52 Sequence of DCIB72 Nucleotide and amino acid sequence of the heavy and light variable regions cloned inframe with the human IgGI Fc and kappa constant regions within the expression vector pDCOrig. Amino acids within boxes represent the Tie-2 Z12 epitope (ILINSLPLV) in H2 and the HepB CD4 epitope (TPPAYRPPNAPIL) in L1. The Hind ⁇ /Afe I and SamHI/Ss/WI restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • ILINSLPLV Tie-2 Z12 epitope
  • TPPAYRPPNAPIL HepB CD4 epitope
  • Figure 53 The role of xenogenic Fc in providing T cell help and the requirement for antigen specific T cell help.
  • mice were immunised at day 0, 7 and 14 with Heavy chain ImmunoBody DNA constructs containing gp100 epitope in CDR H1 or TRP2 epitope in CDR H2 (IB17 and IB18 respectively).
  • splenocytes were analysed by IFN ⁇ elispot assay against gp100 peptide or TRP2 peptide and control. Responses are measured as spots/million splenocytes.
  • Splenocytes from mice immunised with ImmunoBody heavy chain containing TRP2 epitope in CDR H2 were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • C, C57BI/6 mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing gp100 epitope in CDR H1 , TRP2 epitope in CDR H2 and
  • DCIB15 Human IgGI
  • TRP2 epitope in CDR H2 TRP2 epitope in CDR H2
  • HepB CD4 epitope in CDR L1 with murine lgG2a constant region DCIB53.
  • splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide, HepB helper peptide and control. Responses are measured as spots/million splenocytes.
  • D Splenocytes from mice immunised with DCIB15 or DCIB53 were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • HLA-DR4 transgenic mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing gp100DR4 epitope in CDR H1 , TRP2 epitope in CDR H2 and gp100DR7 epitope in CDR H3 Human IgGI (DCIB54) or gp100DR4 epitope in CDR H1 , TRP2 epitope in CDR H2 and gp100DR7 epitope in CDR H3 with murine lgG2a constant region (DCIB64).
  • splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide, gp100DR4 helper peptide and control. Responses are measured as spots/million splenocytes.
  • Splenocytes from mice immunised with DCIB54 or DCIB64 were assayed for avidity to the TRP2 epitope by measuring responses to increasing peptide concentration in IFN ⁇ elispot assay. Responses are measured as spots/million splenocytes and avidity is assigned as the concentration which gives 50% maximal effector function.
  • Nucleotide and amino acid sequence of the murine heavy and light full length chains within the expression vector pDCOrig moigG2a Nucleotide and amino acid sequence of the murine heavy and light full length chains within the expression vector pDCOrig moigG2a. Amino acids within boxes represent theGPI 0021 OM epitope in H1 (TIMDQVPFSV), the TRP2 epitope in H2 (SVYDFFVWL) and the HepB CD4 epitope in L1 (TPPAYRPPNAPIL) in L1.
  • the HindUVAfe I and BamH ⁇ /Hpa ⁇ restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • Figure 55 Sequence of DCIB64
  • Nucleotide and amino acid sequence of the murine heavy and light full length chains within the expression vector pDCOrig moigG2a The stop codon is depicted by an asterisk.
  • Amino acids within boxes represent the HLA-DR7 restricted gp1 OO CD4 epitope (GTG RAM LGTHTM EVTVYH) in H1 , the TRP2 epitope (SVYDFFVWL) in H2 and the HLA-DR4 restricted gp100 CD4 epitope in H3 (WNRQLYPEWTEAQRLD).
  • the HindWUAfe I and BamHVHpal restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • FIG. 56 lmmunoproteasome processing is important in the generation of responses from epitopes within ImmunoBody constructs.
  • HHDII mice were immunised at day 0, 7 and 14 with ImmunoBody constructs containing the gp100 209"217 epitope in CDR H1 (DCIB41 ) or the modified version gp100210M in CDR H1 (DCIB15).
  • splenocytes were analysed by IFN ⁇ elispot assay against gp100 209"217 peptide or gp100210M peptide and control. Responses are measured as spots/million splenocytes.
  • mice were immunised with ImmunoBody DNA (DCIB15) via gene gun, i.m. +/- electroporation or i.d. +/- electroporation at days 0, 7 and 14.
  • splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide, HepB helper peptide and control. Responses are measured as spots/million splenocytes.
  • C57BI/6 mice immunised with ImmunoBody DNA containing the TRP2 epitope in CDR H2 and the HepB CD4 epitope in CDR L1 (DCIB18) demonstrate depigmentation in hair growth at the site of immunisation.
  • Tumour burden in the lungs was assessed at 49 days post tumour challenge. Tumour burden is expressed as a mean tumour area as a percentage of total lung area. Immunised mice were challenged 7 days post final immunisation with 2x10 4 B16F10 IFN ⁇ cells s. c. Tumour size was measured at 3-4 day intervals and mice euthanized once tumour growth exceeded limit.
  • mice were injected with 2x10 4 B16F10 cells s.c.
  • Four days post tumour injection mice were immunised with DCIB52 ImmunoBody DNA. Repeat immunisation were performed at days 1 1 and 18 post tumour injection. Tumour burden was analysed at 3-4 day intervals and mice euthanized once tumour growth exceeded maximum permitted limit. Tumour volume over time was plotted.
  • mice C57BI6 mice were injected with 2x10 4 B16F10 IFN ⁇ cells s.c.
  • Fourteen days post tumour injection mice were immunised with DCIB52 ImmunoBody DNA. Repeat immunisations were performed at days 21 and 28 post tumour injection. Tumour burden was analysed at 3-4 day intervals and mice euthanized once tumour growth exceeded maximum permitted limit. Tumour volume is shown at day 47 post tumour implant.
  • C C57BI6 mice were injected with 2x10 4 B16F10 cells s.c and anti-CD25 antibody i.p. where appropriate.
  • Four days post tumour injection mice were immunised with DCIB52 ImmunoBody DNA or control ImmunoBody DNA. Repeat immunisations were performed at days 1 1 and 18 post tumour injection Immunisation at day 11 was combined with the injection of anti-CTLA-4 antibody i.p. where appropriate.
  • Tumour burden was analysed at 3-4 day intervals and mice euthanized once tumour growth exceeded maximum permitted limit. Tumour volume over time was plotted.
  • Amino acids within boxes represent the HLA- DR7 restricted gp100 CD4 epitope (GTGRAMLGTHTMEVTVYH) in H1 and L3, the TRP2 epitope (SVYDFFVWL) in H2 and the HLA-DR4 restricted gp100 CD4 epitope in H3 and L1 (WNRQLYPEWTEAQRLD).
  • the HindW/Afe I and SamHI/Ss/WI restriction sites utilised in transfer of the variable heavy and light region from the single construct are highlighted.
  • FIG. 61 Immune responses can be generated from ImmunoBody constructs expressed from different vector backbones.
  • C57BI/6 mice were immunised at day 0, 7 and 14 with ImmunoBody DNA constructs containing gp100DR4 epitope in CDR H1 , TRP2 epitope in CDR H2 and gp100DR7 epitope in CDR H3 Human IgGI (DCIB54, B1 -3) an equivalent construct in the pVax vector (VaxDCIB54, C1 -3).
  • splenocytes were analysed by IFN ⁇ elispot assay against TRP2 peptide and control. Responses are measured as spots/million splenocytes.
  • VHd VKb (WO01/88138) within the vectors pSVgptHuigGI and pSVhygHuCk (Biovation Ltd) were amplified by PCR.
  • V H and V L region PCR products were cloned in frame with the human IgGI and kappa constant regions using Hin ⁇ /Afe ⁇ and BamH ⁇ /Bsi ⁇ N ⁇ sites to produce the single chain constructs pOrigHIB and pOrigLIB (see Figures 1 and 2).
  • the sequence of the full- length chimeric heavy and kappa chain was confirmed by the dideoxy chain termination method (Sanger et al, Proceedings of the National Academy of Sciences of the United States of America 1977;74: 5463-7).
  • DNA and translated protein sequences for the chimeric heavy and light chain are shown in Figures 3 and 4 respectively. Locations of the complementarily determining regions (CDR's) are depicted.
  • first round PCR's were set up consisting of 1 ⁇ l of the template plasmid pOrigHIB, 2 ⁇ l dNTPS (2.5mM), 5 ⁇ l 10 x taq polymerase buffer, 1 ⁇ l of forward and reverse primer (25pmols), 5units of taq polymerase (New England Biolabs) made up to a final volume of 50 ⁇ l with sterile distilled water.
  • oligonucleotides L1 , L2, and L3 were designed to replace each of the three CDR's (see Table 2).
  • First round PCR's were set up as described above but with the reverse primer huLiClonR (see Table 2) that binds to the constant region of the human kappa chain and the template pOrigLIB.
  • N epitope DNA sequence
  • Insertion of antigenic epitopes into CDR sites of single chain vectors A number of CD8 CTL and CD4 helper epitopes are listed in Table 3, although any epitope can easily be inserted into any of the sites within the single chain vectors. For example, insertion of the TRP2 epitope into the H2 site of the pOrigHIB vector was achieved as follows.
  • Complementary oligonucleotides were designed to encode nucleotide sequence that on translation expresses the epitope. DNA sequence that encodes the epitope was flanked by the corresponding CDR nucleotides to ensure that, on translation, amino acids were retained and that the sequence remained in frame (see Table 1 ). Primers were sent for synthesis (MWG) and 5' end phosphorylated.
  • Complementary oligonucleotides were resuspended to a final concentration of 1 mg/ml in sterile double distilled water and annealed together by setting up a reaction with 10 ⁇ l of each primer made up to a final volume of 50 ⁇ l with TE buffer. The reaction was cycled for 95° C- 5mins (0.1 Q C/sec), 72 °C - 20mins 0.1 Q C/sec, 55°C- 20mins then held at 4°C
  • the vector pOrigHIB H2 and/ or pOrigHIB H1 H2 was linearised by setting up a Mscl restriction digest (dependent on CDR to be utilised for insertion of epitope) and incubated overnight at 37°C. The digest was electrophoresed on a 1.5% agarose gel and the cut vector purified by gel extraction. To prevent self ligation of the linearised vector, phosphate groups from the 5' ends of the vector were removed by treatment and overnight incubation at 37 5 C with calf intestinal alkaline phosphatase (CIAP) 5 units, 10 ⁇ l 1 O x NEB buffer 3 made up to a final volume of 10O ⁇ l with sterile distilled water.
  • Mscl restriction digest dependent on CDR to be utilised for insertion of epitope
  • the digest was electrophoresed on a 1.5% agarose gel and the cut vector purified by gel extraction.
  • phosphate groups from the 5' ends of the vector were removed by treatment and overnight incubation
  • Dephosphorylated vector was purified and ligations set up with neat, 1/100 and 1/200 dilutions of the annealed oligonucleotides to clone directly into the H2 site using standard techniques. Epitope insertions were confirmed by sequencing within the single vectors using the universal primer CMV forward.
  • pOrigHIB was linearised using the blunt ended restriction endonuclease Nrul located adjacent to the CMV promoter.
  • pOrigLIB was digested with the blunt ended Nrul and Hpal endonucleases to excise the entire light chain expression cassette consisting of the CMV promoter, deimmunised human kappa chain and the BGH polyA signal.
  • pDCOrig contains both the heavy and light chain gene coding sequences combined within the same construct, eliminating intronic sequences and the two vector system. Expression is driven by the high level CMV Immediate Early promoters and other DNA control elements, such as Bovine Growth Hormone polyadenylation signal. The selection marker Zeocin has also been included to maximise expression and efficiency of production. Careful design of this vector has retained the unique restriction enzyme sites at the junctions of the variable and constant regions and provides a quick and easy method to create different combinations of the variable regions (epitope insertions, see Figure 8). Table 4 lists some of the pDcOrig IB constructs generated.
  • a stop codon was incorporated after the CH1 domain of the human IgGI constant region within the construct pDCOrig IB15 using the Quik change site directed mutagenesis kit (Stratagene) and the complementary oligonucleotides origstophuHeCHI Forward and OrigstophuHeCHI reverse primers (see Table 2) as instructed by the manufacturer. Incorporation of the stop codon was confirmed by DNA sequencing ( Figure 9)
  • the human lgG3 constant region was amplified by PCR using huigg3 forward and reverse primers (Table 2) incorporating a Afel and EcoRV respectively with the template pOTB7huigG3 (Image clone 4566267 MGC 45809).
  • the amino acids P233 V234 A235 within the huigG2 constant domain of the construct pDCOrig IB15 huigG2 was also substituted with the huigGI binding motif ELLG.
  • the reverse primer huigG2ELLGRev (Table 2) containing the substitutions and the constitutive restriction site Ahdl was utilised with the forward primer HIBF and the template pDCOrig IB15 human igG2.
  • the fragment was TA TOPO ligated into the vector pCR2.1 .
  • the wild type sequence again was replaced with the section containing the huigGI binding motif using Agel/Ahdl sites of the plasmid pDCOrig IB15 huigG2 ( Figure 16).
  • pDCOrig murine lgG2a plasmids DCIB53 and DCIB63
  • cDNA was synthesised from total RNA isolated from the hybhdoma cell line 337.
  • the forward primer migG2aC1 AfeF2 containing the restriction site Afe1 was used in conjunction with the reverse primer migG2aXbaRA harbouring a Xbal site after the stop codon.
  • PCR fragment was TOPO ligated into the vector pCR2.1.
  • the murine igG2a constant region was excised and cloned inframe with the murine heavy variable region into the Afe1/Xbal sites of the vector pOrigHIB effectively replacing human igG1.
  • a BamHI and Xhol site was removed without altering, on translation, amino acid sequence from the murine igG2a constant region, sequentially by site directed mutagenesis using Quik change site directed mutagenesis kit (Stratagene) and the complimentary primers MoigG2BamHIFOR and REV, MoigG2XholFOR and REV respectively. This generated the single chain ImmunoBody vector pMoOrigHIB ( Figure 17A).
  • a section of pMoOhgHIB containing the MoigG2a constant region was transferred from the single construct into the double expression vector pDCOrig IB15 inframe with the murine heavy variable region using Afel and the single cutter Avrll located in the SV40 promoter to generate the intermediate vector pDCOhglB15MoigG2a hukappa still containing a human kappa region.
  • the cDNA was used as a template with the primers MoLCI BsiF1 containing a BsiWI site and MoLCXhol incorporating a Xhol site after the stop codon.
  • the amplified fragment was TOPO cloned into the vector pCR2.1 as before.
  • the murine kappa region was excised and ligated into the ImmunoBody vector pOrigLIB L1 and pOrigLIB hepB help/L1 replacing the human kappa constant using BsiWI/Xhol generating the intermediate vector pMoLIBLI Bsi and pMoLIB HepB help/L1 Bsi.
  • the lmmunobody system involves transfer of variable regions using a unique restriction site at the junction of the variable and constant regions while the junction between the murine heavy variable and moigG2a constant can accommodate an Afel site (present within all the human immunobody vectors) and not alter amino acid sequence on translation, the region between the murine variable and kappa is problematic. On analysis of sequence at this junction no unique restriction site could be incorporated that would not alter amino acid sequence.
  • the BsiWI site at the junction was removed to revert to wild type sequence. This was achieved by amplifying the entire murine full length chain by overlapping PCR.
  • a first PCR was set up using the forward primer MoKappaSDMfor containing wild type sequence at the junction and flanking region effectively removing BsiWI, the BGH reverse primer and the intermediate light chain vectors pMoLIBLI Bsi and pMoLIB hepB help/L1 Bsi as template respectively.
  • Around a 430bp amplified fragment from the first round of PCR was used as a reverse primer with the forward primer ImmunoLikozFor containing a BamHI site.
  • the amplified full length murine kappa chains were TOPO ligated into pCR2.1 and sequence confirmed.
  • the full length murine kappa chain containing hepB help in the L1 site in pCR2.1 was excised and cloned into the BamHI/Xhol sites of the intermediate double expression vector pDCOriglB15MoigG2a hukappa replacing the human kappa chain to generate the murine double expression vector pDCOriglB GP100210m/H1 TRP2/H2 HepB help/L1 molgG2a (DCIB 53, Figure17 B and 54).
  • the full length murine kappa chain containing an L1 site was excised and cloned into the BamHI/Xhol sites of the intermediate double expression vector pDCOriglB15MoigG2a hukappa replacing the human kappa chain to generate the intermediate murine double expression vector pDCOriglB15molgG2a with an empty L1 site.
  • the complimentary 5' phosphorylated primers wtkappavarU for and rev (Table2) were annealed and inserted into the L1 site after linearization with EcoRV as described above.
  • the resultant 51 1 bp PCR fragment was pCR2.1 TOPO ligated and confirmed by sequencing.
  • the EM7 promoter and a section of the zeocin gene was excised using Nhel and Fsel from pCR2.1 and cloned directly into pOrigHIB H1 effectively removing the SV40 promoter.
  • the Nhel site resides before the SV40 promoter while the Fsel recognition sequence is a single cutter within the zeocin gene of the vector.
  • the lmmunobody full length human igG1 heavy chain was excised from the construct DCIB54 using Hindi 11 and Xbal and inserted into these sites within the MCS of the vector pVaxi ( Figurei 8 A).
  • pVaxlB54HIB was linearised using the blunt ended restriction endonuclease Nrul located adjacent to the CMV promoter.
  • pOrigLIB ( Figure18 B) was digested with the blunt ended Nrul and Hpal endonucleases to excise the entire light chain expression cassette consisting of the CMV promoter, lmmunobody human kappa chain and the BGH polyA signal.
  • pVaxDCIB54 After gel electrophoresis, isolation and gel extraction of the linerised vector pVaxlB54HIB and the light chain expression cassette the vector was dephosphorylated and light chain expression cassette ligated to form the construct pVaxDCIB54 ( Figure18 C). Orientation of the light chain cassette within pVaxDCIB54 was confirmed by restriction analysis. pVaxDCIB54 retains the same unique restriction sites at the variable/ constant region junction permitting easy exchange of variable regions between all human isotype single and double chain lmmunobody vectors.
  • TRP2 cDNA synthesised from 5 ⁇ g of total RNA isolated from the cell line B16F10 was used as a template for the amplification of full length murine tyrosinase related protein 2 (TRP2) using the primers murine TRP2 forward and reverse (Table 2) with incorporation of a Hindi 11 or EcoRV site respectively.
  • Full length TRP2 was ligated into the Hindlll/EcoRV multiple cloning site of the vector pOhgHIB.
  • Full length murine GP100 was also amplified from the cDNA using the designed murine GP100 forward and reverse primers containing EcoRV and Xhol sites respectively (Table 1 ).
  • the PCR product was cloned into the EcoRV/Xhol sites of the mammalian expression vector pCDNA3 (Invitrogen). Both plasmids were identified by restriction analysis and confirmed by DNA sequencing.
  • Tissue culture supernatant containing expressed ImmunoBody or purified ImmunoBody protein (50 ⁇ l) was added to the wells, in triplicate, and plates were incubated for 1 hr at room temperature. Plates were washed with 1 % FSG/PBS and bound ImmunoBody was detected by adding 50 ⁇ I/well of peroxidase-conjugated anti-human IgG, Fc specific antibody (Sigma A0170) or anti-human kappa light chain antibody (Sigma A7164), diluted 1/2000 in 1 % FSG/PBS, and incubated 1 hr at room temperature. Plates were washed with 1 % FSG/PBS and developed by adding TMB substrate(R & D Systems) at 50 ⁇ l/well. Absorbance was measured at 650nm in a VERSA max microplate reader (Molecular Devices).
  • T cell subsets in vivo were performed by injection of 400 ⁇ g anti-CD25 antibody (PC61 ) i.p. four days prior to immunisation or 200 ⁇ g anti-CTLA-4 antibody i.p. concurrent with secondary immunisation.
  • splenocytes (5x10 6 AmI) were cocultured at 37 ° C with syngeneic, irradiated (20Gy), peptide pulsed lipopolysacchahde (LPS) blasts (0.5 to 1 x10 6 cells/ml) in 2ml RPMI-1644 with 10% FBS, 2mM glutamine, 2OmM HEPES buffer, 100 units/ml penicillin, l OO ⁇ g/ml "1 streptomycin and 10 "5 M 2-mercaptoethanol in 24 well plates.
  • syngeneic, irradiated (20Gy), peptide pulsed lipopolysacchahde (LPS) blasts 0.5 to 1 x10 6 cells/ml
  • 2ml RPMI-1644 with 10% FBS, 2mM glutamine, 2OmM HEPES buffer, 100 units/ml penicillin, l OO ⁇ g/ml "1 streptomycin and 10 "5 M 2-mercaptoethanol in 24 well plates.
  • LPS blasts were obtained by activating splenocytes (1.5x10 6 cells/ml) with 25 ⁇ g/ml LPS (Sigma) and 7 ⁇ g/ml dextran sulphate (Pharmacia, Milton Keynes, UK) for 3 days at 37 ° C. Before use, 2x10 7 LPS blasts were cultured with 100 ⁇ g/ml synthetic peptide for 1 hr. Cultures were assayed for cytotoxic activity on day 6 in a 51 Cr- release assay.
  • 51 Cr-release assay Target cells were labelled for 1 hr with 1.85MBq sodium ( 51 Cr) chromate
  • Elispot assays were performed using murine IFN ⁇ capture and detection reagents according to the manufacturer's instructions (Mabtech, Sweden).
  • anti-IFN ⁇ antibodies were coated onto wells of 96-well Immobilin-P plate and replicate wells were seeded with 5x10 5 splenocytes.
  • Synthetic peptides (at a variety of concentrations) or 5x10 4 target melanoma cells were added to these wells and incubated for 40hrs at 37 ° C. After incubation, captured IFN ⁇ was detected with by a biotinylated anti-IFN ⁇ antibody and development with a strepatavidin alkaline phosphatase and chromogenic substrate.
  • CD8 T cells were analysed and counted using an automated plate reader (CTL). Functional avidity was calculated as the concentration mediating 50% maximal effector function using a graph of effector function versus peptide concentration.
  • CTL plate reader
  • Functional avidity was calculated as the concentration mediating 50% maximal effector function using a graph of effector function versus peptide concentration.
  • Depletion of CD8 T cells from splenocyte populations was performed using CD8 Dynabeads (Dynal) according to manufacturer's instructions and then added to ex vivo elispot assay. Tumour studies
  • mice were randomised into treatment groups and immunised at weekly intervals for five weeks. Between the third and fourth immunisation they were challenged by i.v. injection into the tail vein with 1x10 4 B16F10 IFN ⁇ melanoma cells. When injected i.v., B16F10 cells migrate to the lungs to form metastases. Mice were monitored for signs of tumour growth and distress. At day 49 post tumour challenge, mice were euthanised and lungs analysed for the presence of metastases. Spleens were analysed for the presence of epitope and tumour specific immune responses in ex vivo elispot assay.
  • HHDII mice were immunised at weekly intervals for three weeks and 7 days post-final immunisation were challenged s.c. in the right flank with 2x10 4 B16F10 HHD melanoma cells. Tumour growth was monitored at 3-4 day intervals and size of the tumour was measured using a calliper.
  • Example 1 ImmunoBody constructs produce low levels of intact antibody
  • Stable CHO-S cell transfectants were made with an ImmunoBody construct containing the gp100 epitope IMDQVPFSV and the TRP2 epitope SVYDFFVWL in CDR H1 and CDR H2 respectively with the HepB CD4 epitope TPPAYRPPNAPIL in CDR L1 (DCIB15; Figure 19).
  • ImmunoBody protein by sandwich elisa. Plates were coated with anti-human IgG Fc specific antibody and supernatant added. Bound ImmunoBody was detected using an anti-human Fc specific HRP antibody to detect heavy chain. Heavy chain was detected in the supernatant at a concentration of approximately 1 ⁇ g/ml compared to the control ( Figure 20a). ImmunoBody was purified from the supernatant using a protein A affinity column and analysed for presence of ImmunoBody. Purification of ImmunoBody yielded far lower quantities of protein than previously expected compared to the control ( Figure 20b).
  • ImmunoBody constructs were analysed for the expression of both heavy chain and intact antibody in the supernatant of transfected cells by sandwich ELISA. Constructs with the HepB CD4 epitope in CDR L1 and the SIINFEKL epitope in CDR H2 (DCIB24; Figure 21 ) or the gp100 epitope IMDQVPFSV and the TRP2 epitope SVYDFFVWL in CDR H1 and CDR H2 respectively with the HepB CD4 epitope TPPAYRPPNAPIL in CDR L3 (DCIB25; Figure 22) were also tested. Plates were coated with anti-human IgG Fc specific antibody and supernatant added.
  • Bound ImmunoBody was detected using an anti-human Fc specific HRP antibody to detect heavy chain or an anti-human kappa chain specific HRP antibody to detect intact ImmunoBody.
  • ImmunoBody transfectants show high level of heavy chain secretion but very low levels of intact ImmunoBody ( Figure 20c and d).
  • Example 2 - CTL epitopes incorporated into ImmunoBody framework are processed and presented to elicit an immune response in vivo
  • the previously-published CTL epitope from TRP2, aa280-288 (Bloom et al, The Journal of Experimental Medicine 1997;185: 453-9), was engineered into the CDR H2 region of the ImmunoBody construct alongside a Hepatitis B universal CD4 epitope in CDR L1 (DCIB18; Figure 30).
  • C57BI/6 mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody DNA via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for TRP2 specific responses.
  • mice immunised with ImmunoBody DNA demonstrated considerable TRP2 peptide specific responses compared to control but lower level responses specific for the HepB CD4 peptide ( Figure 31 a).
  • the avidity of the TRP2 specific responses were also studied by peptide titration in IFN ⁇ elispot. Over the fifteen mice tested within five different experiments, the avidity of the responses ranges from 10 "9 M to 10 "11 M peptide. A representative example is shown in Figure 31 b.
  • splenocytes were stimulated with TRP2 peptide pulsed LPS blasts in vitro for 6 days and analysed in a chromium release assay against B16F10 melanoma cells.
  • Splenocytes from ImmunoBody DNA immunised mice demonstrated superior lysis of both B16F10 cells, which have low levels of surface MHC class I, and of B16F10 I FNa cells, which have high surface MHC class I expression compared to that of B16F10 line that expresses no H-2Kb molecules (B16F10 siKb).
  • the abolition of killing against the B16F10 siKb cell line demonstrates that killing is CD8 dependent and restricted through H-2Kb ( Figure 31 d).
  • TRP2 SVYDFFVWL CD8 epitope incorporated into the CDR H2 region of the ImmunoBody framework is processed and presented to elicit high frequency responses mediated via MHC class I.
  • the HepB CD4 epitope is also processed and presented in the context of MHC class Il to elicit good CD4 mediated responses from DNA immunisation.
  • TRP2 epitope specific responses were also analysed from other TRP2 epitope containing constructs using identical methodology. Incorporation of the TRP2 epitope into CDRs within the heavy chain resulted in high frequency peptide specific responses ( Figure 31 e). In contrast incorporation of CTL epitopes within the light chain resulted in a significant reduction in CTL frequency (DCIB36). Analysis of the avidity of the TRP2 epitope specific responses reveals that they are of high avidity when generated from epitopes within the heavy chain but this is considerably lower upon expression of epitopes from the light chain ( Figure 31 f). High frequency high avidity helper responses where observed for all constructs ( Figure 31 g). Suggesting that secretion of heavy chain was an advantage for stimulating CTL responses but not for helper responses.
  • Example 3 ImmunoBody DNA immunisation is better than peptide immunisation or immunisation with whole antigen
  • TRP2 and helper peptide specific responses generated in ImmunoBody immunised mice were far superior in magnitude to those elicited by peptide immunisation or immunisation with the whole TRP2 antigen ( Figure 32a). Further analysis of the avidity of these peptide specific responses revealed that responses generated by mice immunised with ImmunoBody DNA have greater than a log higher avidity than those from peptide immunised individuals ( Figure 32b).
  • ImmunoBody immunisation was also compared to immunisation with DC + peptide.
  • C57BI/6 mice received three weekly immunisations with DNA or DC + peptide.
  • TRP2 peptide specific responses were of comparable frequency but ImmunoBody immunised mice generated higher avidity responses compared to those immunised with DC + peptide ( Figure 32d). This is also demonstrated when these responses were analysed for ability to kill B16F10 melanoma cells in vitro ( Figure 32e).
  • the responses generated by ImmunoBody immunisation showed higher killing of B16F10 melanoma at lower effector to target ratio than responses from DC + peptide immunised mice. They also showed higher specific lysis of the B16F20 siKb melanoma line which has knocked down levels of H-2Kb.
  • ImmunoBody constructs containing the H-2Kb restricted Ovalbumin epitope, SIINFEKL, and the anchor modified HLA-A2 restricted gp100 epitope, IMDQVPFSV (210M) were compared with the corresponding epitope peptide immunisation in C57BI/6 or HHDII mice respectively.
  • Analysis of the responses after the final immunisation reveals that ImmunoBody DNA immunised mice generate higher frequency peptide specific responses compared to peptide immunised mice ( Figure 32f and g). These responses were also analysed for avidity by peptide titration.
  • ImmunoBody immunisation elicits significantly higher avidity responses than peptide immunisation ( Figure 32h and i).
  • TRP2 specific response generated by the ImmunoBody DNA vaccine is far superior to that generated by either synthetic peptide or whole TRP2 antigen.
  • evidence from clinical trials suggests that the presence of a high frequency of tumour specific CD8 T cells does not necessarily lead to tumour regression and generally in vaccine trials the objective clinical response rate is very low (Rosenberg et al, J Immunol 2005;175: 6169-76; Rosenberg et al, Nature Medicine 2004;10: 909-15). It is now becoming clear that factors other than frequency such as functional avidity of tumour specific T cells and route of priming are major determinants in maximising vaccine efficacy. A number of groups have shown that high avidity CD8 T cells demonstrate superior anti-tumour activity (Alexander- Miller, Immunologic research, 2005;31 : 13-24; Hodge et al, J Immunol
  • Example 4 Multiple epitopes can be processed from CDR H2 site
  • H-2Kb restricted epitope SIINFEKL (DCIB24; Figure 21 ) from ovalbumin and the H-2Kd restricted Hepatitis B epitope IPQSLDSWWTSL (DCIB21 ; Figure 33) were engineered into the H2 site in the heavy variable region.
  • These ImmunoBody constructs also contained a I-Ab restricted (TPPAYRPPNAPIL) epitope Hepatitis B CD4 epitope or I-Ad restricted Influenza haemagluttinin (FERFEIFPKE) epitope in the CDR L1 site in the light variable region.
  • I-Ab restricted TPPAYRPPNAPIL
  • FERFEIFPKE I-Ad restricted Influenza haemagluttinin
  • C57BI/6 or Balb/c mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody DNA via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for the presence of epitope specific CD8 and CD4 responses.
  • Example 5 Multiple CTL epitopes can be processed from the variable region
  • epitopes can be processed and presented from the variable region and not solely the CDR regions, epitopes were incorporated into the CDR H1 site with the removal of part of the framework region.
  • Example epitopes are the modified HLA-A2 restricted epitopes IMDQVPFSV (DCIB17; Figure 35) from gp100 and FLPATLTMV from Tie-2 (DCIB26; Figure 36). ImmunoBody constructs also contained the Hepatitis B CD4 epitope in the CDR L1 site.
  • HLA-A2 transgenic mice HHDII mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody DNA via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for the presence of epitope specific CD8 and CD4 responses.
  • HHDII mice elicited high frequency gp100 210M epitope specific responses with reasonable responses to the HepB CD4 epitope ( Figure 37a).
  • Responses in HHDII mice immunised with the Tie2 epitope containing construct were not of as high frequency but considerable responses were generated specific for both the Tie2 epitope and the HepB CD4 epitope ( Figure 37b).
  • variable region Data in this example indicates that epitopes inserted within the variable region can be processed and presented to elicit an immune response in vivo. It is also apparent that this is not restricted to one epitope sequence.
  • Example 6 Multiple CTL responses can be generated from different epitopes within the same ImmunoBody construct
  • HLA-A2 restricted gp100 epitope IMDQVPFSV was engineered into the CDR H1 site alongside the TRP2 epitope SVYDFFVWL which is also restricted through HLA-A2 in the CDR H2 site of the same construct.
  • the HepB CD4 epitope was present in the CDR L1 site (DCIB15; Figure 19).
  • HHDII mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody DNA via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for the presence of epitope specific CD8 and CD4 responses.
  • Figure 38a shows that responses are generated specific for both the gp100 and TRP2 epitopes, although the frequency of the TRP2 specific responses are lower. Responses to the HepB CD4 peptide are also generated.
  • the avidity of the TRP2 specific responses were also studied by peptide titration in IFN ⁇ elispot. The avidity of the responses ranges from 10 "10 M to 10 "11 M peptide for the gp100 epitope and 10 "9 M to 10 "10 M peptide for the TRP2 epitope. Representative examples are shown in Figure 38b.
  • splenocytes were stimulated with TRP2 and gp100 peptide pulsed LPS blasts in vitro for 6 days and analysed in a chromium release assay against peptide labelled T2 cells and B16F1 O HHD melanoma cells. Specific killing of B16F10 HHD melanoma line compared to the control B16F10 melanoma line. Responses also demonstrated specific lysis of peptide labelled T2 cells compared to control ( Figure 38c).
  • the immunodominant epitope is the epitope with the highest affinity for MHC class I.
  • mice are immunised with the construct containing both gp100 and TRP2 CD8 epitopes are compared to those immunised with a construct containing only the TRP2 CD8 epitope, the frequency of the TRP2 response decreases (Figure 38d).
  • mice with these constructs in the same site results in significant loss of the TRP2 peptide specific response. This suggests that the SIINFEKL epitope is dominant over the TRP2 epitope.
  • Example 7 Non anchor residue modifications can enhance T cell recognition
  • modified gp100 epitope IMDQVPFSV is immunodominant and has a high affinity for HLA-A2 (predicted using the SYFPEITHI algorithm and demonstrated in T2 stabilisation assay - Table 5). Since the wild type gp100 epitope ITDQVPFSV is not immunogenic, modifications were made at non anchor residues that would have a similar HLA-A2 binding affinity to the wild type epitope but also enhance the immunogenicity. These modified epitopes were engineered into the CDR H1 site of the ImmunoBody construct and tested alongside the wild type epitope (DCIB37, DCIB40, DCIB41 , DCIB42, DCIB43; Figures 39-43).
  • HHDII mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody heavy chain DNA alone via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for the presence of epitope specific CD8 responses. Two modifications (F7L and F7I; DCIB37; Figure 39, DCIB40; Figure 40) to the wild type gp100 epitope which retain affinity for HLA-A2 (Table 5) demonstrated superior ability to induce epitope specific immune responses compared to the wild type epitope ( Figure 44a). Table 5
  • Example 8 Multiple CD4 helper responses can be processed and presented to elicit an immune response in vivo
  • CD4 helper epitopes were engineered independently into the CDR L1 site of the ImmunoBody construct. These included the I-Ad restricted epitope FERFEIFPKE (DCIB21 ; Figure 33) from Influenza haemagluttinin, the I-Ab restricted epitope TPPAYRPPNAPIL from HBcAg (DCIB15; Figure 19) and the HLA-DR4 restricted epitope WNRQLYPEWTEAQRLD from gp100 (DCIB35; Figure 45).
  • I-Ad restricted epitope FERFEIFPKE DCIB21 ; Figure 33
  • I-Ab restricted epitope TPPAYRPPNAPIL from HBcAg
  • HLA-DR4 restricted epitope WNRQLYPEWTEAQRLD from gp100
  • CDRL1 Constructs incorporating the epitope into CDRL1 (DCIB35; Figure 45), CDRH3 (DCIB54; Figure 29) or CDRL3 (DCIB50; Figure 47) were used to immunise HLA-DR4 transgenic mice three times at weekly intervals.
  • Figure 46d shows that helper epitope can be efficiently processed from different CDRs to elicit high frequency helper responses.
  • Example 9 - CTL responses are partially dependent upon secreted heavy chain but helper responses do not require secreted light chain
  • CD4 T cell epitopes are processed from proteins that are acquired exogenously and CD8 T cell epitopes from endogenously produced proteins. There is evidence now for the cross presentation of epitopes from exogenously acquired antigen to elicit a CD8 T cell mediated response. This route of priming has also been proposed to be more efficient in the development of CD8 T cell-mediated immune responses. Recently there have been similar findings for CD4-mediated responses. Mounting evidence suggests that CD4 T cell epitopes derived from intracellular proteins can be processed and presented in the context of MHC class II.
  • ImmunoBody constructs containing the HLA- A2 restricted gp100 epitope IMDQVPFSV in the CDR H1 site and the I-Ab restricted HepB helper epitope TPPAYRPPNAPIL in the CDR L1 site were made without leader sequences on the heavy chain or light chain ( Figures 10 and 11 ).
  • HHDII mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody DNA via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for the presence of epitope specific CD8 and CD4 T cell responses. When the responses were analysed for gp100 specific CD8 response, it was observed that removal of the leader sequence from the heavy chain of the ImmunoBody construct resulted in a decrease in epitope specific responses however the CD4 responses was not affected ( Figure 48a). Removal of the leader sequence from the heavy chain affected secretion of heavy chain by transfected CHO-S cells ( Figure 48b).
  • C57BI/6 mice were immunised three times at weekly intervals intradermal ⁇ with ImmunoBody DNA via the gene gun. Splenocytes were subsequently analysed by IFN ⁇ elispot for the presence of epitope specific CD8 and CD4 T cell responses.
  • the Fc stop construct results in lower secretion of the truncated heavy chain which may explain the reduced response.
  • An ImmunoBody encoding TRP-2 was therefore engineered with an lgG2 (DCIB33) and an lgG3 constant region (DCIB65) the former should not bind to CD64 but can bind to CD32 and may also bind to Fc receptor IV in mice. Human lgG3 can bind to both CD32 and CD64. Both ImmunoBodies stimulated strong CTL responses (Figure 49e). This suggests that Fc targeting is not a strong component of the indirect presentation.
  • T cell epitope which is that, in contrast to most self antigens, it is an inert carrier that does not express regulatory epitopes.
  • An ImmunoBodyTM expressing either a gp100 epitope or a TRP-2 epitope stimulated a high frequency, high avidity T cell response (frequency 1/10 3 avidity 10 "10 M) whereas immunisation with the whole gp100 of TRP-2 antigen stimulated T cells with low frequency and avidity (frequency 1 /10 5 avidity 10 "7 M).
  • CD25 depletion partially restored the response to the antigen but ImmunoBody was still 100 fold superior ( Figure 50a and b).
  • mice were immunised with the native Tie2 C200hFc DNA construct (Ramage et al, Int. J. Cancer 2004;110:245-250) and splenocytes were screened for peptide specific IFN ⁇ responses in an ELISPOT assay.
  • splenocytes were screened for peptide specific IFN ⁇ responses in an ELISPOT assay.
  • a separate group of mice were immunized with C200hFc following treatment with PC61 mAb, as before, 4 days prior to DNA immunisation.
  • mice that were immunised with the native C200HFc DNA construct did not mount an IFN ⁇ response that recognised Z83, regardless of whether the animals were depleted of CD25 + regulatory T cells prior to immunisation or not. There were no significant IFN ⁇ responses to any of the new peptides tested from animals that were not depleted of regulatory T cells prior to immunisation, with the exception of Z284 which appeared to stimulate a response in one animal (M3) with a mean of 69 SFC/million splenocytes ( Figure 50c and d).
  • M1 and M3 From the animals that were depleted of regulatory T cells prior to DNA immunisation, 2/3 animals (M1 and M3) demonstrated an IFN ⁇ response to restimulation with Z282 peptide, with mean values of 320 and 94 SFC/million splenocytes respectively. M1 also demonstrated a partial response to restimulation with Z285, with a mean of 85 SFC/million splenocytes.
  • mice immunised with Z282 mounted peptide-specific IFN ⁇ responses, even when immunised in the presence of CD25 + regulatory T cells.
  • Mouse 3 of the non-depleted animals mounted the highest response, with a mean value of 215 SFC/million cells.
  • the highest response from the depleted animals was observed from mouse 2 with a mean value of 137 SFC/million cells ( Figure 5Oe and f).
  • Example 12 The role of xenogenic Fc in providing T cell help and the requirement for antigen specific T cell help
  • T cell help during the priming. It was originally conceived that this would be provided by the Hep B foreign helper epitope encoded within the light chain. Indeed strong helper responses were generated to this epitope. However as the heavy chain was secreted and the light chain was not although the hep B epitope could have provided help for direct presentation when both chains would be produced by the same APC it is unlikely that it could be providing help for the indirectly presented heavy chain as this is unlikely to be taken up by the same antigen presenting cell. Mice were therefore immunised with a DNA vector only encoding heavy chain. High frequency, high avidity CTL responses were still generated ( Figure 53 a and b).
  • a mouse lgG2a construct was therefore assessed for secretion of Heavy and light chains (Figure 49g) and screened for generation of immune responses (DCIB53 figure 54). Although it still gave high frequency high avidity T cell responses these were not as strong as the equivalent human construct suggesting that the xenogenic Fc was providing linked help ( Figure 53c and d).
  • An HLA-DR4 gp100 epitope was then incorporated into the mouse lgG2a construct (DCIB64, Figure 55) to provide both linked help for CTL generation but also antigen specific T cell help to stimulate inflammation within the tumour environment. These constructs stimulate high frequency and high avidity CTL and helper responses ( Figure 53e and f).
  • a hlgG1 construct expressing the same epitope can be used in human patients.
  • Example 13 - lmmunoproteasome processing is important in the generation of responses from epitopes within ImmunoBody constructs
  • the immunoproteasome has the ability to alter the array of epitopes generated from self antigens as it possess a different pattern of cleavage. In some cases, new epitopes are generated upon upregulation of the immunoproteasome and in others epitopes are destroyed. There is evidence that the immunoproteasome is unable to generate several epitopes derived from melanoma antigens namely MelanA/MART-1 , gp100 209"217 and Tyrosinase 369"377 (Chapiro ef a/ 2006. J Immunol; 176: 1053-61 ).
  • a HLA-A2 restricted peptide derived from VEGFR2 (aa 773-781 VIAMFFWLL) and two modified hTERT peptides (aa 572-580 YLFFYRKSV and aa 988-997 YLQVNSLQTV) were also tested for generation of responses from ImmunoBody constructs.
  • These epitopes were initially discovered by in silico epitope prediction and peptide immunisation therefore negating the requirement for proteasomal processing. However they are presented upon the surface of host endothelial/tumour cells which suggests they are processed from whole antigen via the constitutive proteasome.
  • Example 14 Different immunisation methods are efficient at eliciting immune responses from ImmunoBody vaccine
  • ImmunoBody vaccine has been shown to be effective at eliciting high frequency and avidity CD8 and CD4 responses when administered via gene gun. ImmunoBody vaccine was subsequently tested for generation of T cell responses using other methods of immunisation.
  • C57BI/6 mice were immunised with ImmunoBody DNA containing the TRP2 epitope in CDRH2 via either the i.d. or i.m. route. Immunisations were combined with and without electroporation and performed three times at weekly intervals.
  • mice immunised with gene gun show high frequency TRP2 peptide specific responses. These are comparable in mice immunised either via i.m. or i.d. route combined with electroporation. Immunisation via i.m. or i.d. route in absence of electroporation generated lower frequency TRP2 peptide specific responses ( Figure 57a). All TRP2 peptide specific responses are of high avidity as measured by peptide titration ( Figure 57b).
  • Example 15 ImmunoBody immunisation induces vitiligo-like depigmentation and protects against tumour challenge
  • mice immunised with ImmunoBody DNA generate immune responses capable of cytotoxic activity against the highly metastatic and poorly immunogenic tumour cell line B16F10, the vaccine was tested for protective efficacy in vivo.
  • mice were immunised with IB DNA (DCIB18; Figure 30) via gene gun into shaved skin of the abdomen at five weekly intervals. Part way through the schedule of immunisations, mice were injected i.v with 1 x10 4 B16F10 cells expressing IFN ⁇ which forms metastatic tumours in the lung. When the hair was permitted to grow back after last immunisation, mice immunised with ImmunoBody DNA were observed to have growth of white hair at the site of immunisation ( Figure 58a). Seven weeks post tumour cell injection, mice were sacrificed and the number of internal and external lung metastases analysed. ImmunoBody DNA immunised mice exhibited a significant reduction in the number of lung metastases compared to untreated control mice ( Figure 58b).
  • mice were also immunised with IB DNA (DCIB18) via gene gun at three weekly intervals. Seven days post final immunisation mice were challenged with 2x10 4 B16F10 cells expressing IFN ⁇ subcutaneously. Mice were monitored for tumour growth and survival. Mice were euthanized once tumours reached the maximum limit according to Home Office regulations. ImmunoBody DNA immunised mice exhibited significantly slower subcutaneous tumour growth and prolonged survival ( Figure 58c & d).
  • the TRP2 specific response is CD8 mediated as depletion of the CD8+ cells abrogates the response.
  • CD8 T cells have been identified as a major player in anti-tumour immunity and our results show that ImmunoBody DNA immunisation elicits in vivo anti-tumour immunity in a mouse model. All immunised mice with no signs of disease exhibited vitiligo-like depigmentation of fur at the site of immunisation.
  • ImmunoBody immunisation has previously shown to significantly protect against tumour challenge.
  • the vaccine was subsequently tested for efficacy in a therapeutic setting.
  • mice were injected s.c. with 2x10 4 B16F10 tumour cells.
  • Four days post injection mice were immunised with ImmunoBody DNA containing TRP2 epitope in CDRH2 or control ImmunoBody DNA. Repeat immunisations were performed at days 1 1 and 18 post tumour injection. Tumour growth was monitored at 3-4 day intervals.
  • ImmunoBody immunised mice demonstrate a significant delay in growth of the aggressive B16F10 melanoma compared to control immunised mice ( Figure 59a).
  • mice were injected with 2x10 4 tumour cells s.c. and immunised at day 14 with ImmunoBody DNA or control DNA. Repeat immunisation were performed at days 21 and 28 post tumour injection. ImmunoBody immunised mice exhibited significantly lower tumour growth than control immunised mice at day 47 post tumour injection ( Figure 59b). Previous data has suggested that depletion of T regulatory cells enhances generation of immune responses therefore an anti-tumour study was performed. In this study mice were injected with 2x10 4 B16F10 tumour cells s.c. and immunised at day 4, 11 and 18 with ImmunoBody DNA or control
  • Example 17 - Immune responses can be generated from ImmunoBody constructs expressed from different vector backbones.
  • ImmunoBody constructs were expressed from different vector backbones.
  • ImmunoBody construct containing gp100DR7 epitope in CDRH1 , TRP2 epitope in CDRH2 and gp100DR4 epitope in CDRH3 with wildtype light chain was engineered into the double expression vectors
  • HLA-DR4 transgenic mice were immunised via gene gun three times at weekly intervals and responses analysed ex vivo by IFN ⁇ elispot assay.
  • mice immunised with the ImmunoBody construct in the Orig vector (B1 -3) demonstrate similar frequency epitope responses compared to the lmmunobody cionstruct in the pVax vector (C1 -3) ( Figure 61 ).
  • ImmunoBody technology has superior ability to elicit high frequency and avidity CD8 and CD4 immune responses from a non- immunogenic antibody framework that can efficiently prevent tumour growth in vivo. It has the ability to target up to six different antigens simultaneously and has the capability to avert the problem of regulatory T cells that often occurs when whole antigen immunogens are used.
  • This technology presents a novel approach to vaccination and demonstrates the potential for the ImmunoBody system to be used as a multivalent vaccine for many other cancer types and micro-organism related diseases.
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